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CSAT ┬╖ 132 questions

Arithmetic: percentage, ratio, averages, time & work

Every UPSC CSAT question on this topic, 2016тАУ2026, newest first. Tap an option to check yourself; the answer and explanation open below it.

Arithmetic: percentage, ratio, averages, time & work questions per year: 2016: 16, 2017: 11, 2018: 8, 2019: 15, 2020: 15, 2021: 16, 2022: 13, 2023: 2, 2024: 11, 2025: 9, 2026: 16 Asked in 11 of 11 years ┬╖ most in 2026 (16)
Timed ┬╖ 30 minutes a set Practise Arithmetic: percentage, ratio, averages, time & work as timed tests 7 sets of about 20 questions with UPSC's CSAT marking. Start practising

UPSC syllabus: тАЬBasic numeracy (numbers and their relations, orders of magnitude, etc.) (Class X level), Data interpretation (charts, graphs, tables, data sufficiency etc. тАФ Class X level);тАЭ Sub-topics in the detailed syllabus тЖТ

Showing 91тАУ120 of 132, newest first.

рдПрдХ рд╣рдЬрд╛рд░ (1000) рдореАрдЯрд░ рдХреА рдПрдХ рджреМрдбрд╝ рдореЗрдВ X, Y рдФрд░ Z рддреАрди рдкреНрд░рддрд┐рдпреЛрдЧреА рд╣реИрдВ ред рдорд╛рди рд▓реАрдЬрд┐рдП рдХрд┐ рд╡реЗ рд╕рднреА рд╡рд┐рднрд┐рдиреНрди рдПрдХрд╕рдорд╛рди рдЧрддрд┐рдпреЛрдВ рд╕реЗ рджреМрдбрд╝рддреЗ рд╣реИрдВ ред Y, X рд╕реЗ 40 m рдЖрдЧреЗ рд╕реЗ рджреМрдбрд╝рдирд╛ рд╢реБрд░реВ рдХрд░рддрд╛ рд╣реИ рдФрд░ Z, X рд╕реЗ 64 m рдЖрдЧреЗ рд╕реЗ рджреМрдбрд╝рдирд╛ рд╢реБрд░реВ рдХрд░рддрд╛ рд╣реИ ред рдпрджрд┐ Y рдФрд░ Z рдХреЛ 1000 m рдХреА рдПрдХ рджреМрдбрд╝ рдореЗрдВ рдкреНрд░рддрд┐рд╕реНрдкрд░реНрдзрд╛ рдХрд░рдиреА рд╣реИ, рддреЛ Z, Y рд╕реЗ рдХрд┐рддрдиреЗ рдореАрдЯрд░ рдЖрдЧреЗ рд╕реЗ рджреМрдбрд╝рдирд╛ рд╢реБрд░реВ рдХрд░реЗрдЧрд╛ ?

Read this question in English

X, Y and Z are three contestants in a race of 1000 m. Assume that all run with different uniform speeds. X gives Y a start of 40 m and X gives Z a start of 64 m. If Y and Z were to compete in a race of 1000 m, how many metres start will Y give to Z?

(a) 20 ┬╖ (b) 25 ┬╖ (c) 30 ┬╖ (d) 35

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) 25

While X runs 1000 m, Y runs 960 m and Z 936 m. So while Y runs 1000 m, Z runs 1000 ├Ч 936/960 = 975 m, and Y can give Z a start of 25 m.

  1. X gives Y 40 m: while X runs 1000 m, Y runs 960 m.
  2. X gives Z 64 m: in the same time Z runs 936 m.
  3. Speed ratio Y : Z = 960 : 936.
  4. While Y runs 1000 m, Z runs 1000 ├Ч 936/960 = 975 m.
  5. Start Y gives Z = 1000 тИТ 975 = 25 m.

Remember ┬╖ Turn 'starts' into distances run in the same time, then scale to the new race length.

Question and answer: UPSC's official GS Paper II (2019, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдИрдирд╛ рдЕрдкрдиреЗ рдорд╛рддрд╛-рдкрд┐рддрд╛ рдХреЗ рд╡рд┐рд╡рд╛рд╣ рдХреЗ 4 рд╡рд░реНрд╖ рдмрд╛рдж рдкреИрджрд╛ рд╣реБрдИ ред рдЙрд╕рдХреА рдорд╛рддрд╛ рдЙрд╕рдХреЗ рдкрд┐рддрд╛ рд╕реЗ рддреАрди рд╡рд░реНрд╖ рдЫреЛрдЯреА рд╣реИ рдФрд░ рдИрдирд╛ рд╕реЗ, рдЬреЛ 13 рд╡рд░реНрд╖ рдХреА рд╣реИ, 24 рд╡рд░реНрд╖ рдмрдбрд╝реА рд╣реИ ред рдИрдирд╛ рдХреЗ рдкрд┐рддрд╛ рдХрд╛ рдХрд┐рд╕ рдЙрдореНрд░ рдореЗрдВ рд╡рд┐рд╡рд╛рд╣ рд╣реБрдЖ рдерд╛ ?

Read this question in English

Ena was born 4 years after her parentsтАЩ marriage. Her mother is three years younger than her father and 24 years older than Ena, who is 13 years old. At what age did EnaтАЩs father get married?

(a) 22 years ┬╖ (b) 23 years ┬╖ (c) 24 years ┬╖ (d) 25 years

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) 23 рд╡рд░реНрд╖

Ena is 13, her mother 37 and her father 40. The marriage took place 13 + 4 = 17 years ago, when the father was 40 тИТ 17 = 23.

  1. Ena = 13; mother = 13 + 24 = 37; father = 37 + 3 = 40.
  2. The marriage was 4 years before Ena's birth: 13 + 4 = 17 years ago.
  3. Father's age at marriage = 40 тИТ 17 = 23 years.

Remember ┬╖ Fix everyone's present age first, then move all of them back by the same number of years.

Question and answer: UPSC's official GS Paper II (2019, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рд░рд╛рдХреЗрд╢ рдХреЗ рдкрд╛рд╕ рдПрдХ рд╡рд┐рд╢рд┐рд╖реНрдЯ рдХрдВрдкрдиреА рдХреЗ 8 рдореЛрдмрд╛рдЗрд▓ рд╣реИрдВрдбрд╕реЗрдЯ рдЦрд░реАрджрдиреЗ рдХреЗ рд▓рд┐рдП рдзрдирд░рд╛рд╢рд┐ рдереА ред рд▓реЗрдХрд┐рди рдЦреБрджрд░рд╛ рд╡реНрдпрд╛рдкрд╛рд░реА рдиреЗ рдЙрд╕ рдЦрд╛рд╕ рд╣реИрдВрдбрд╕реЗрдЯ рдкрд░ рдмрд╣реБрдд рдЕрдЪреНрдЫреА рдЫреВрдЯ рдХрд╛ рдкреНрд░рд╕реНрддрд╛рд╡ рджрд┐рдпрд╛ ред рд░рд╛рдХреЗрд╢ рдЕрдкрдиреЗ рдкрд╛рд╕ рдХреА рдзрдирд░рд╛рд╢рд┐ рд╕реЗ 10 рдореЛрдмрд╛рдЗрд▓ рд╣реИрдВрдбрд╕реЗрдЯ рдЦрд░реАрдж рд╕рдХрд╛ ред рдЦреБрджрд░рд╛ рд╡реНрдпрд╛рдкрд╛рд░реА рджреНрд╡рд╛рд░рд╛ рдкреНрд░рд╕реНрддрд╛рд╡рд┐рдд рдЫреВрдЯ рдХрд┐рддрдиреА рдереА ?

Read this question in English

Rakesh had money to buy 8 mobile handsets of a specific company. But the retailer offered very good discount on that particular handset. Rakesh could buy 10 mobile handsets with the amount he had. What was the discount the retailer offered?

(a) 15% ┬╖ (b) 20% ┬╖ (c) 25% ┬╖ (d) 30%

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) 20%

The same money buys 10 handsets instead of 8, so the new price is 8/10 of the old one тАФ a 20% discount. 25% is the rise in quantity, not the fall in price.

  1. Let the price be тВ╣100; Rakesh has 8 ├Ч 100 = тВ╣800.
  2. тВ╣800 now buys 10 handsets, so the discounted price = тВ╣80.
  3. Discount = (100 тИТ 80)/100 ├Ч 100% = 20%.

Remember ┬╖ With fixed money, price ├Ч quantity is constant: quantities 8 : 10 mean prices 10 : 8.

Question and answer: UPSC's official GS Paper II (2019, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рджрд┐рдпрд╛ рдЧрдпрд╛ рд╣реИ рдХрд┐ 100 рд╡рд┐рджреНрдпрд╛рд░реНрдерд┐рдпреЛрдВ рдХрд╛ рдФрд╕рдд рдЕрдВрдХ 40 рд╣реИ ред рдмрд╛рдж рдореЗрдВ рдпрд╣ рдкрд╛рдпрд╛ рдЧрдпрд╛ рдХрд┐ рдПрдХ рд╡рд┐рджреНрдпрд╛рд░реНрдереА рдХрд╛ рдЕрдВрдХ 53 рдерд╛ рдЬрд┐рд╕реЗ рднреВрд▓ рд╕реЗ 83 рдкрдврд╝рд╛ рдЧрдпрд╛ ред рд╕рдВрд╢реЛрдзрд┐рдд рдФрд╕рдд рдЕрдВрдХ рдХрд┐рддрдирд╛ рд╣реИ ?

Read this question in English

The average marks of 100 students are given to be 40. It was found later that marks of one student were 53 which were misread as 83. The corrected mean marks are

(a) 39 ┬╖ (b) 39.7 ┬╖ (c) 40 ┬╖ (d) 40.3

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) 39┬╖7

The total was overstated by 83 тИТ 53 = 30 marks, so the correct total is 3970 and the mean is 39.7.

  1. Recorded total = 100 ├Ч 40 = 4000.
  2. Excess from the misreading = 83 тИТ 53 = 30.
  3. Correct total = 4000 тИТ 30 = 3970; correct mean = 3970/100 = 39.7.
  4. Shortcut: the mean falls by 30/100 = 0.3.

Remember ┬╖ One wrong entry shifts the mean by (wrong тИТ right) ├╖ n.

Question and answer: UPSC's official GS Paper II (2019, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдХрд┐рд╕реА рд╕рдореВрд╣ рдореЗрдВ 15 рд╡реНрдпрдХреНрддрд┐ рд╣реИрдВ; рдЬрд┐рдирдореЗрдВ рд╕реЗ 7 рдлреНрд░реЗрдВрдЪ рдкрдврд╝ рд╕рдХрддреЗ рд╣реИрдВ, 8 рдЕрдВрдЧреНрд░реЗрдЬрд╝реА рдкрдврд╝ рд╕рдХрддреЗ рд╣реИрдВ, рдЬрдмрдХрд┐ 3 рдЗрди рджреЛрдиреЛрдВ рднрд╛рд╖рд╛рдУрдВ рдореЗрдВ рд╕реЗ рдХреЛрдИ рднреА рднрд╛рд╖рд╛ рдирд╣реАрдВ рдкрдврд╝ рд╕рдХрддреЗ ред рдХрд┐рддрдиреЗ рд╡реНрдпрдХреНрддрд┐ рдпрдерд╛рд░реНрдерддрдГ рдПрдХ рднрд╛рд╖рд╛ рдкрдврд╝ рд╕рдХрддреЗ рд╣реИрдВ ?

Read this question in English

In a group of 15 people; 7 can read French, 8 can read English while 3 of them can read neither of these two languages. The number of people who can read exactly one language is

(a) 10 ┬╖ (b) 9 ┬╖ (c) 5 ┬╖ (d) 4

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) 9

Twelve people read at least one language. French and English readers add to 15, so 3 read both, and 12 тИТ 3 = 9 read exactly one.

  1. At least one language = 15 тИТ 3 = 12.
  2. Both = 7 + 8 тИТ 12 = 3.
  3. Exactly one = 12 тИТ 3 = 9 (French only 4, English only 5).

Remember ┬╖ Exactly one = (at least one) тИТ (both); get 'both' from A + B тИТ (at least one).

Question and answer: UPSC's official GS Paper II (2019, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдХрд┐рд╕реА рдкрд░рд┐рд╡рд╛рд░ рдореЗрдВ рджреЛ рдмрдЪреНрдЪреЗ рд╣реИрдВ рдФрд░ рдЙрдирдХреЗ рдорд╛рддрд╛-рдкрд┐рддрд╛ рд╣реИрдВ ред рдмрдЪреНрдЪреЛрдВ рдФрд░ рдЙрдирдХреА рдорд╛рддрд╛ рдХреЗ рд╡рдЬрд╝рдиреЛрдВ рдХрд╛ рдФрд╕рдд 50 kg рд╣реИ ред рдмрдЪреНрдЪреЛрдВ рдФрд░ рдЙрдирдХреЗ рдкрд┐рддрд╛ рдХреЗ рд╡рдЬрд╝рдиреЛрдВ рдХрд╛ рдФрд╕рдд 52 kg рд╣реИ ред рдпрджрд┐ рдкрд┐рддрд╛ рдХрд╛ рд╡рдЬрд╝рди 60 kg рд╣реИ, рддреЛ рдорд╛рддрд╛ рдХрд╛ рд╡рдЬрд╝рди рдХрд┐рддрдирд╛ рд╣реИ ?

Read this question in English

A family has two children along with their parents. The average of the weights of the children and their mother is 50 kg. The average of the weights of the children and their father is 52 kg. If the weight of the father is 60 kg, then what is the weight of the mother?

(a) 48 kg ┬╖ (b) 50 kg ┬╖ (c) 52 kg ┬╖ (d) 54 kg

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (d) 54 kg

Children plus mother weigh 150 kg and children plus father 156 kg, so the father is 6 kg heavier than the mother. With the father at 60 kg, the mother weighs 54 kg.

  1. Children + mother = 3 ├Ч 50 = 150 kg.
  2. Children + father = 3 ├Ч 52 = 156 kg.
  3. Father тИТ mother = 156 тИТ 150 = 6 kg.
  4. Mother = 60 тИТ 6 = 54 kg.
  5. Check: children = 156 тИТ 60 = 96, and 96 + 54 = 150.

Remember ┬╖ When two averages share members, subtract the totals тАФ the shared part cancels.

Question and answer: UPSC's official GS Paper II (2019, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рд╕реБрдиреАрддрд╛ рдХрд╛рдЧрдЬрд╝ рдХреЗ рдПрдХ рдкрддреНрд░рдХ рдХреЛ рддреАрди рдЯреБрдХрдбрд╝реЛрдВ рдореЗрдВ рдХрд╛рдЯрддреА рд╣реИ ред рдкрд╣рд▓реЗ рдЯреБрдХрдбрд╝реЗ рдХреА рд▓рдВрдмрд╛рдИ рдПрдХ рдЕрдВрдХ рд╡рд╛рд▓реА рддреАрди рд╡рд┐рд╖рдо рдЕрднрд╛рдЬреНрдп рд╕рдВрдЦреНрдпрд╛рдУрдВ рдХреЗ рдФрд╕рдд рдХреЗ рдмрд░рд╛рдмрд░ рд╣реИ ред рджреВрд╕рд░реЗ рдЯреБрдХрдбрд╝реЗ рдХреА рд▓рдВрдмрд╛рдИ рдкрд╣рд▓реЗ рдЯреБрдХрдбрд╝реЗ рдХреА рд▓рдВрдмрд╛рдИ рдФрд░ рддреАрд╕рд░реЗ рдЯреБрдХрдбрд╝реЗ рдХреА рдПрдХ-рддрд┐рд╣рд╛рдИ рд▓рдВрдмрд╛рдИ рдХреЗ рдпреЛрдЧ рдХреЗ рдмрд░рд╛рдмрд░ рд╣реИ ред рддреАрд╕рд░реЗ рдЯреБрдХрдбрд╝реЗ рдХреА рд▓рдВрдмрд╛рдИ рдЕрдиреНрдп рджреЛ рдЯреБрдХрдбрд╝реЛрдВ рдХреА рд▓рдВрдмрд╛рдЗрдпреЛрдВ рдХреЗ рдпреЛрдЧ рдХреЗ рдмрд░рд╛рдмрд░ рд╣реИ ред рдХрд╛рдЧрдЬрд╝ рдХреЗ рдореВрд▓ рдкрддреНрд░рдХ рдХреА рд▓рдВрдмрд╛рдИ рдХрд┐рддрдиреА рд╣реИ ?

Read this question in English

Sunita cuts a sheet of paper into three pieces. Length of first piece is equal to the average of the three single digit odd prime numbers. Length of the second piece is equal to that of the first plus one-third the length of the third. The third piece is as long as the other two pieces together. The length of the original sheet of paper is

(a) 13 units ┬╖ (b) 15 units ┬╖ (c) 16 units ┬╖ (d) 30 units

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (d) 30 рдЗрдХрд╛рдИ

The single-digit odd primes are 3, 5 and 7, so the first piece is 5 units. With the third piece T, the second is 5 + T/3 and T = 10 + T/3, so T = 15, the second piece is 10 and the sheet is 30 units.

  1. Single-digit odd primes: 3, 5, 7; average = 15/3 = 5, so the first piece = 5.
  2. Let the third piece be T; the second = 5 + T/3.
  3. Third = first + second: T = 5 + 5 + T/3 тЖТ 2T/3 = 10 тЖТ T = 15.
  4. Second = 5 + 15/3 = 10.
  5. Sheet = 5 + 10 + 15 = 30 units.
  6. Check: the third piece (15) equals 5 + 10.

Remember ┬╖ If one part equals the sum of the others, the whole is twice that part.

Question and answer: UPSC's official GS Paper II (2019, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдиреАрдЪреЗ рджрд┐рдП рдЧрдП рдЪрд┐рддреНрд░ рдореЗрдВ A рдФрд░ B рджреЛ рд╡рд╛рд╣рдиреЛрдВ рдХреЗ рд╡реЗрдЧ рдХреЗ рдЖрд▓реЗрдЦ (рдЧреНрд░рд╛рдл) рджрд┐рдП рдЧрдП рд╣реИрдВред рд╕рд░рд▓рд░реЗрдЦрд╛ OKP рдХрд┐рд╕реА рднреА рдХреНрд╖рдг рдореЗрдВ рд╡рд╛рд╣рди A рдХреЗ рд╡реЗрдЧ рдХреЛ рджрд░реНрд╢рд╛рддреА рд╣реИ, рдЬрдмрдХрд┐ рдХреНрд╖реИрддрд┐рдЬ рд╕рд░рд▓рд░реЗрдЦрд╛ CKD рдХрд┐рд╕реА рднреА рдХреНрд╖рдг рдореЗрдВ рд╡рд╛рд╣рди B рдХреЗ рд╡реЗрдЧ рдХреЛ рджрд░реНрд╢рд╛рддреА рд╣реИред рдЪрд┐рддреНрд░ рдореЗрдВ, D рд╡рд╣ рдмрд┐рдиреНрджреБ рд╣реИ рдЬрд╣рд╛рдБ P рд╕реЗ рдХреНрд╖реИрддрд┐рдЬ рд░реЗрдЦрд╛ CKD рдкрд░ рд▓рдореНрдм рдЗрд╕ рдкреНрд░рдХрд╛рд░ рдорд┐рд▓рддрд╛ рд╣реИ рдХрд┐ PD = 1/2 LD :

VelocityтАУtime graph: A's velocity rises along a straight line from the origin O through K to P; B's velocity is the horizontal line CтАУKтАУD; P lies above time L, D is on B's line directly below P, and PL is dotted down to the time axis.
From UPSC's question paper.

рд╕рдордп рдЕрдВрддрд░рд╛рд▓ OL рдореЗрдВ рд╡рд╛рд╣рди A рдФрд░ рд╡рд╛рд╣рди B рджреНрд╡рд╛рд░рд╛ рддрдп рдХреА рдЧрдИ рджреВрд░рд┐рдпреЛрдВ рдХреЗ рдмреАрдЪ рдХреНрдпрд╛ рдЕрдиреБрдкрд╛рдд рд╣реИ?

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The figure drawn below gives the velocity graphs of two vehicles A and B. The straight line OKP represents the velocity of vehicle A at any instant, whereas the horizontal straight line CKD represents the velocity of vehicle B at any instant. In the figure, D is the point where perpendicular from P meets the horizontal line CKD such that PD = 1/2 LD:

What is the ratio between the distances covered by vehicles A and B in the time interval OL?

(a) 1: 2 ┬╖ (b) 2: 3 ┬╖ (c) 3: 4 ┬╖ (d) 1: 1

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (c) 3 : 4

Distance is the area under a velocityтАУtime graph. A's distance is the triangle OLP and B's is the rectangle of height LD over OL; since PL = 3/2 ├Ч LD, the triangle is 3/4 of the rectangle.

  1. Let LD (B's constant velocity) = 2 units; then PD = 1 and A's velocity at time L is PL = PD + DL = 3.
  2. Distance of B in time OL = rectangle = OL ├Ч 2 = 2 ├Ч OL.
  3. Distance of A in time OL = triangle OLP = 1/2 ├Ч OL ├Ч 3 = 1.5 ├Ч OL.
  4. Ratio A : B = 1.5 : 2 = 3 : 4.

Remember ┬╖ On a velocityтАУtime graph, distance = area under the line: a triangle for steady acceleration from rest, a rectangle for constant speed.

Question and answer: UPSC's official GS Paper II (2018, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). Permalink ┬╖

200 рдореАрдЯрд░ рд▓рдореНрдмреА рдПрдХ рдЯреНрд░реЗрди 40 рдХрд┐ре░ рдореАре░ рдкреНрд░рддрд┐ рдШрдВрдЯрд╛ рдХреА рджрд░ рд╕реЗ рдЪрд▓ рд░рд╣реА рд╣реИред рд░реЗрд▓рд╡реЗ рд▓рд╛рдЗрди рдХреЗ рдирд┐рдХрдЯ рдЦрдбрд╝реЗ рдХрд┐рд╕реА рд╡реНрдпрдХреНрддрд┐ рдХреЛ рдпрд╣ рдЯреНрд░реЗрди рдХрд┐рддрдиреЗ рд╕реЗрдХрдВрдб рдореЗрдВ рдкрд╛рд░ рдХрд░реЗрдЧреА?

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A train 200 metres long is moving at the rate of 40 kmph. In how many seconds will it cross a man standing near the railway line?

(a) 12 ┬╖ (b) 15 ┬╖ (c) 16 ┬╖ (d) 18

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (d) 18

To pass a man standing still, the train covers only its own length, 200 m. At 40 km/h, which is 100/9 m/s, that takes 18 seconds.

  1. Distance to cover = length of the train = 200 m (the man adds no length).
  2. Speed: 40 km/h = 40 ├Ч 5/18 = 100/9 m/s.
  3. Time = 200 ├╖ (100/9) = 18 seconds.
  4. Check: in 18 s at 40 km/h the train covers 40,000 ├Ч 18 ├╖ 3600 = 200 m.

Remember ┬╖ A train passing a pole or a standing person covers only its own length; convert km/h to m/s by multiplying by 5/18.

Question and answer: UPSC's official GS Paper II (2018, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдПрдХ рдкреБрд╕реНрддрдХ рд╡рд┐рдХреНрд░реЗрддрд╛ рдиреЗ тВ╣ x рдкреНрд░рддрд┐ рдкреБрд╕реНрддрдХ рдХреА рджрд░ рд╕реЗ рднреВрдЧреЛрд▓ рдХреА тАШaтАЩ рдкреБрд╕реНрддрдХреЗрдВ рдмреЗрдЪреАрдВ, тВ╣ (x + 2) рдкреНрд░рддрд┐ рдкреБрд╕реНрддрдХ рдХреА рджрд░ рд╕реЗ рдЗрддрд┐рд╣рд╛рд╕ рдХреА тАШa + 2тАЩ рдкреБрд╕реНрддрдХреЗрдВ рдмреЗрдЪреАрдВ рддрдерд╛ тВ╣ (x тИТ 2) рдкреНрд░рддрд┐ рдкреБрд╕реНрддрдХ рдХреА рджрд░ рд╕реЗ рдЧрдгрд┐рдд рдХреА тАШa тИТ 2тАЩ рдкреБрд╕реНрддрдХреЗрдВ рдмреЗрдЪреАрдВред рдЙрд╕рдХреА рдХреБрд▓ рдмрд┐рдХреНрд░реА (тВ╣ рдореЗрдВ) рдХрд┐рддрдиреА рд╣реИ?

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A bookseller sold тАШaтАЩ number of Geography textbooks at the rate of тВ╣x per book, тАШa + 2тАЩ number of History textbooks at the rate of тВ╣(x + 2) per book and тАШa тИТ 2тАЩ number of Mathematics textbooks at the rate of тВ╣(x тИТ 2) per book. What is his total sale in тВ╣?

(a) 3x + 3a ┬╖ (b) 3ax + 8 ┬╖ (c) 9ax ┬╖ (d) x┬│a┬│

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) 3ax + 8

Total sale = ax + (a + 2)(x + 2) + (a тИТ 2)(x тИТ 2). The terms 2a + 2x and тИТ2a тИТ 2x cancel, leaving 3ax + 8.

  1. Geography: a ├Ч x = ax.
  2. History: (a + 2)(x + 2) = ax + 2a + 2x + 4.
  3. Mathematics: (a тИТ 2)(x тИТ 2) = ax тИТ 2a тИТ 2x + 4.
  4. Sum: 3ax + 8.
  5. Check with a = 3, x = 5: 15 + 5 ├Ч 7 + 1 ├Ч 3 = 53, and 3 ├Ч 3 ├Ч 5 + 8 = 53.

Remember ┬╖ Check algebraic options by putting small numbers into both the question and each option.

Question and answer: UPSC's official GS Paper II (2018, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рджреЛ рд╡реНрдпрдХреНрддрд┐ A рдФрд░ B рдХрд┐рд╕реА рд╡реГрддреНрддреАрдп рдорд╛рд░реНрдЧ рдкрд░ рджреМрдбрд╝ рд░рд╣реЗ рд╣реИрдВред рдкреНрд░рд╛рд░рдВрдн рдореЗрдВ B, A рд╕реЗ рдЖрдЧреЗ рд╣реИ рддрдерд╛ рдЙрдирдХреА рд╕реНрдерд┐рддрд┐рдпрд╛рдБ рд╡реГрддреНрдд рдХреЗ рдХреЗрдиреНрджреНрд░ рдкрд░ 30┬░ рдХрд╛ рдХреЛрдг рдмрдирд╛рддреА рд╣реИрдВред рдЬрдм A, рдЙрд╕ рдмрд┐рдиреНрджреБ рдкрд░ рдкрд╣реБрдБрдЪрддрд╛ рд╣реИ рдЬреЛ рдХрд┐ рдЙрд╕рдХреЗ рдкреНрд░рд╛рд░рдореНрднрд┐рдХ рдмрд┐рдиреНрджреБ рд╕реЗ рд╡реНрдпрд╛рд╕рддрдГ рд╕рдореНрдореБрдЦ рд╣реИ, рддрдм рд╡рд╣ B рд╕реЗ рдорд┐рд▓рддрд╛ рд╣реИред A рдФрд░ B рдХреА рдЪрд╛рд▓реЛрдВ рдореЗрдВ рдХреНрдпрд╛ рдЕрдиреБрдкрд╛рдд рд╣реИ, рдпрджрд┐ рд╡реЗ рдПрдХрд╕рдорд╛рди рдЪрд╛рд▓ рд╕реЗ рджреМрдбрд╝ рд░рд╣реЗ рд╣реИрдВ?

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Two persons, A and B are running on a circular track. At the start, B is ahead of A and their positions make an angle of 30┬░ at the centre of the circle. When A reaches the point diametrically opposite to his starting point, he meets B. What is the ratio of speeds of A and B, if they are running with uniform speeds?

(a) 6: 5 ┬╖ (b) 4: 3 ┬╖ (c) 6: 1 ┬╖ (d) 4: 2

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (a) 6 : 5

A covers half the track, 180┬░. B started 30┬░ ahead and is caught at that same point, so B covered 180┬░ тИТ 30┬░ = 150┬░ in the same time. The speeds are in the ratio 180 : 150 = 6 : 5.

  1. A runs from his start to the diametrically opposite point: an arc of 180┬░.
  2. B started 30┬░ ahead in the direction of running and is met there: B runs 180┬░ тИТ 30┬░ = 150┬░.
  3. Same time, so speed ratio = arc ratio = 180 : 150 = 6 : 5.

Remember ┬╖ On a circular track, measure distances as angles; in equal time, the speed ratio equals the ratio of arcs covered.

Question and answer: UPSC's official GS Paper II (2018, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдХрд┐рд╕реА рдкрд░реАрдХреНрд╖рд╛ рдореЗрдВ рдкрд╛рд╕ рд╣реЛрдиреЗ рдХреЗ рд▓рд┐рдП рдПрдХ рд╡рд┐рджреНрдпрд╛рд░реНрдереА рдХреЛ 40% рдЕрдВрдХ рдЪрд╛рд╣рд┐рдПред рдорд╛рди рд▓реАрдЬрд┐рдП рдХрд┐ рдЙрд╕реЗ 30 рдЕрдВрдХ рдорд┐рд▓рддреЗ рд╣реИрдВ рддрдерд╛ рд╡рд╣ 30 рдЕрдВрдХреЛрдВ рд╕реЗ рдЕрдиреБрддреНрддреАрд░реНрдг рд╣реЛ рдЬрд╛рддрд╛ рд╣реИ, рддреЛ рдкрд░реАрдХреНрд╖рд╛ рдореЗрдВ рдЕрдзрд┐рдХрддрдо рдЕрдВрдХ рдХрд┐рддрдиреЗ рд╣реИрдВ?

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A student has to get 40% marks to pass in an examination. Suppose he gets 30 marks and fails by 30 marks, then what are the maximum marks in the examination?

(a) 100 ┬╖ (b) 120 ┬╖ (c) 150 ┬╖ (d) 300

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (c) 150

Scoring 30 and falling 30 short means the pass mark is 60. If 60 is 40% of the maximum, the maximum is 60 ├╖ 0.4 = 150.

  1. Pass mark = marks scored + shortfall = 30 + 30 = 60.
  2. 40% of maximum = 60, so maximum = 60 ├Ч 100 ├╖ 40 = 150.
  3. Check: 40% of 150 = 60, and 60 тИТ 30 = 30.

Remember ┬╖ Pass mark = marks scored + shortfall; divide it by the pass percentage to get the maximum marks.

Question and answer: UPSC's official GS Paper II (2018, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдХреЛрдИ рджреБрдХрд╛рдирджрд╛рд░ рдХрд┐рд╕реА рд╡рд╕реНрддреБ рдХреЛ тВ╣ 40 рдореЗрдВ рдмреЗрдЪрдХрд░ X % рд▓рд╛рдн рдХрдорд╛рддрд╛ рд╣реИред рддрдерд╛рдкрд┐, рдЬрдм рд╡рд╣ рдЙрд╕ рд╡рд╕реНрддреБ рдХреЛ тВ╣ 20 рдореЗрдВ рдмреЗрдЪрддрд╛ рд╣реИ, рддреЛ рдЙрд╕реЗ рдЙрддрдиреЗ рд╣реА рдкреНрд░рддрд┐рд╢рдд рдХреА рд╣рд╛рдирд┐ рд╣реЛрддреА рд╣реИред рд╡рд╕реНрддреБ рдХреА рдореВрд▓ рд▓рд╛рдЧрдд рдХрд┐рддрдиреА рд╣реИ?

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A shopkeeper sells an article at тВ╣40 and gets X% profit. However, when he sells it at тВ╣20, he faces same percentage of loss. What is the original cost of the article?

(a) тВ╣10 ┬╖ (b) тВ╣20 ┬╖ (c) тВ╣30 ┬╖ (d) тВ╣40

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (c) тВ╣ 30

An equal percentage profit and loss on the same cost means the two selling prices lie equally far above and below the cost. The cost is the average of тВ╣40 and тВ╣20, i.e. тВ╣30 (profit and loss both 33тЕУ%).

  1. Let the cost be C. Then 40 = C(1 + X/100) and 20 = C(1 тИТ X/100).
  2. Adding the two: 60 = 2C, so C = тВ╣30.
  3. Check: тВ╣40 is 33тЕУ% above тВ╣30, and тВ╣20 is 33тЕУ% below it.

Remember ┬╖ Same percentage profit and loss on one cost price: the cost is the average of the two selling prices.

Question and answer: UPSC's official GS Paper II (2018, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдПрдХ рд▓рд┐рдлреНрдЯ рдореЗрдВ 18 рд╡рдпрд╕реНрдХ рдпрд╛ 30 рдмрдЪреНрдЪреЛрдВ рдХреЛ рд▓реЗ рдЬрд╛рдиреЗ рдХреА рдХреНрд╖рдорддрд╛ рд╣реИред рд▓рд┐рдлреНрдЯ рдореЗрдВ 12 рд╡рдпрд╕реНрдХреЛрдВ рдХреЗ рд╕рд╛рде рдХрд┐рддрдиреЗ рдмрдЪреНрдЪреЗ рдЖ рд╕рдХрддреЗ рд╣реИрдВ?

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A lift has the capacity of 18 adults or 30 children. How many children can board the lift with 12 adults?

(a) 6 ┬╖ (b) 10 ┬╖ (c) 12 ┬╖ (d) 15

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) 10

18 adults take the same space as 30 children, so one adult equals 5/3 of a child. 12 adults use the space of 20 children, leaving room for 10.

  1. 18 adults = 30 children, so 1 adult = 30/18 = 5/3 children.
  2. 12 adults = 12 ├Ч 5/3 = 20 children's worth of space.
  3. Room left = 30 тИТ 20 = 10 children.
  4. Check: 12 adults fill 12/18 = 2/3 of the lift; the remaining 1/3 of 30 children is 10.

Remember ┬╖ Convert everything to one unit (here child-spaces), subtract what is used, and read off what remains.

Question and answer: UPSC's official GS Paper II (2018, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдХрд┐рд╕реА рд╡реНрдпрдХреНрддрд┐ рдиреЗ тВ╣22,800 рдХреАрдордд рдХрд╛ рд░реЗрдлреНрд░реАрдЬрд░реЗрдЯрд░ 12┬╖5% рдЪрдХреНрд░рд╡реГрджреНрдзрд┐ рдмреНрдпрд╛рдЬ (рд╡рд╛рд░реНрд╖рд┐рдХ) рдкрд░ рдЦрд░реАрджрд╛ред рдкрд╣рд▓реЗ рд╡рд░реНрд╖ рдХреЗ рдЕрдВрдд рдкрд░ рдЙрд╕рдиреЗ тВ╣8,650 рдПрд╡рдВ рджреВрд╕рд░реЗ рд╡рд░реНрд╖ рдХреЗ рдЕрдВрдд рдкрд░ тВ╣9,125 рдЪреБрдХрд╛рдПред рдЛрдг рдкреВрд░рд╛ рдЪреБрдХрд╛рдиреЗ рдХреЗ рд▓рд┐рдП рдЙрд╕реЗ рддреАрд╕рд░реЗ рд╡рд░реНрд╖ рдХреЗ рдЕрдВрдд рдореЗрдВ рдХрд┐рддрдиреЗ рд░реБрдкрдпреЗ рдХрд╛ рднреБрдЧрддрд╛рди рдХрд░рдирд╛ рд╣реЛрдЧрд╛?

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A person bought a refrigerator worth тВ╣22,800 with 12.5% interest compounded yearly. At the end of first year he paid тВ╣8,650 and at the end of second year тВ╣9,125. How much will he have to pay at the end of third year to clear the debt?

(a) тВ╣9,990 ┬╖ (b) тВ╣10,000 ┬╖ (c) тВ╣10,590 ┬╖ (d) тВ╣11,250

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (d) тВ╣11,250

Add a year's interest (12.5%, one-eighth) to the balance and subtract each payment. The balance falls to тВ╣17,000 after year 1 and тВ╣10,000 after year 2, so year 3 needs тВ╣10,000 ├Ч 1.125 = тВ╣11,250.

  1. Year 1: 22,800 ├Ч 1.125 = 25,650; after paying 8,650 the balance is 17,000.
  2. Year 2: 17,000 ├Ч 1.125 = 19,125; after paying 9,125 the balance is 10,000.
  3. Year 3: 10,000 ├Ч 1.125 = 11,250 clears the debt.
  4. Check: тВ╣10,000 is only the balance at the start of year 3; it still earns a year's interest.

Remember ┬╖ For instalments at compound interest, roll the balance forward: add the year's interest, subtract the payment. 12.5% is one-eighth.

Question and answer: UPSC's official GS Paper II (2018, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдпрджрд┐ рдРрд╕реА рдХреЛрдИ рдиреАрддрд┐ рд╣реИ рдХрд┐ рдХрд┐рд╕реА рд╕рдореБрджрд╛рдп рдХреА рдПрдХ-рддрд┐рд╣рд╛рдИ (1/3) рдЖрдмрд╛рджреА рдкреНрд░рддрд┐ рд╡рд░реНрд╖ рдПрдХ рд╕реНрдерд╛рди рдХреЛ рдЫреЛрдбрд╝рдХрд░ рдХрд┐рд╕реА рджреВрд╕рд░реЗ рд╕реНрдерд╛рди рдкрд░ рдЪрд▓реА рдЬрд╛рдП, рддреЛ рдЫрдард╡реЗрдВ рд╡рд░реНрд╖ рдХреЗ рдмрд╛рдж рдЙрд╕ рд╕рдореБрджрд╛рдп рдХреА рд╢реЗрд╖ рдмрдЪреА рдЖрдмрд╛рджреА рдХреНрдпрд╛ рд╣реЛрдЧреА, рдпрджрд┐ рдЗрд╕ рдЕрд╡рдзрд┐ рдХреЗ рджреМрд░рд╛рди рдЬрдирд╕рдВрдЦреНрдпрд╛ рдореЗрдВ рдЖрдЧреЗ рдФрд░ рдХреЛрдИ рд╡реГрджреНрдзрд┐ рди рд╣реБрдИ рд╣реЛ?

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If there is a policy that 1/3rd of a population of community has migrated every year from one place to some other place, what is the leftover population of that community after the sixth year, if there is no further growth in the population during this period?

(a) 16/243rd part of the population ┬╖ (b) 32/243rd part of the population ┬╖ (c) 32/729th part of the population ┬╖ (d) 64/729th part of the population

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (d) рдЬрдирд╕рдВрдЦреНрдпрд╛ рдХрд╛ 64/729рд╡рд╛рдБ рднрд╛рдЧ

Each year one-third leaves, so two-thirds of the previous year's population remains. The fraction compounds, so after six years the population left is (2/3)тБ╢ = 64/729 of the original.

  1. After one year, 1 тИТ 1/3 = 2/3 of the population remains.
  2. The same fraction applies to what is left each year, so after 6 years the remainder is (2/3)тБ╢.
  3. (2/3)тБ╢ = 2тБ╢/3тБ╢ = 64/729.
  4. Check: the denominator must be 3тБ╢ = 729 and the numerator 2тБ╢ = 64; only (d) has both.

Remember ┬╖ Repeated fractional loss compounds: after n rounds of losing 1/k, the remainder is (1 тИТ 1/k)тБ┐, not 1 тИТ n/k.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рднрд┐рдиреНрди рдКрдБрдЪрд╛рдЗрдпреЛрдВ рдХреЗ рддреАрди рдЦрдореНрднреЗ X, Y рдФрд░ Z рд╣реИрдВред рддреАрди рдордХрдбрд╝рд┐рдпрд╛рдБ A, B рдФрд░ C рдХреНрд░рдорд╢рдГ рдЗрди рдЦрдореНрднреЛрдВ рдкрд░ рдПрдХ рд╣реА рд╕рдордп рдкрд░ рдЪрдврд╝рдирд╛ рд╢реБрд░реВ рдХрд░рддреА рд╣реИрдВред рдПрдХ рдкреНрд░рдпрд╛рд╕ рдореЗрдВ A, X рдкрд░ 6 cm рдЪрдврд╝рддреА рд╣реИ рдХрд┐рдиреНрддреБ 1 cm рдиреАрдЪреЗ рдлрд┐рд╕рд▓ рдЬрд╛рддреА рд╣реИред B, Y рдкрд░ 7 cm рдЪрдврд╝рддреА рд╣реИ рдХрд┐рдиреНрддреБ 3 cm рдиреАрдЪреЗ рдлрд┐рд╕рд▓ рдЬрд╛рддреА рд╣реИред C, Z рдкрд░ 6┬╖5 cm рдЪрдврд╝рддреА рд╣реИ рдХрд┐рдиреНрддреБ 2 cm рдиреАрдЪреЗ рдлрд┐рд╕рд▓ рдЬрд╛рддреА рд╣реИред рдпрджрд┐ рдЙрдирдореЗрдВ рд╕реЗ рдкреНрд░рддреНрдпреЗрдХ рдордХрдбрд╝реА рдХреЛ рдЦрдореНрднреЗ рдХреЗ рд╢реАрд░реНрд╖ рддрдХ рдкрд╣реБрдБрдЪрдиреЗ рдХреЗ рд▓рд┐рдП 40 рдкреНрд░рдпрд╛рд╕ рдХрд░рдирд╛ рдкрдбрд╝рддрд╛ рд╣реИ, рддреЛ рд╕рдмрд╕реЗ рдЫреЛрдЯреЗ рдЦрдореНрднреЗ рдХреА рдКрдБрдЪрд╛рдИ рдХреНрдпрд╛ рд╣реИ?

Read this question in English

There are three pillars X, Y and Z of different heights. Three spiders A, B and C start to climb on these pillars simultaneously. In one chance, A climbs on X by 6 cm but slips down 1 cm. B climbs on Y by 7 cm but slips down 3 cm. C climbs on Z by 6.5 cm but slips down 2 cm. If each of them requires 40 chances to reach the top of the pillars, what is the height of the shortest pillar?

(a) 161 cm ┬╖ (b) 163 cm ┬╖ (c) 182 cm ┬╖ (d) 210 cm

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) 163 cm

A spider does not slip back in the chance in which it reaches the top, so height = 39 net gains + one full climb. That gives X = 201 cm, Y = 163 cm and Z = 182 cm; the shortest pillar is 163 cm.

  1. Net gain per chance: A = 6 тИТ 1 = 5 cm, B = 7 тИТ 3 = 4 cm, C = 6.5 тИТ 2 = 4.5 cm.
  2. In the 40th chance each spider reaches the top and does not slip, so height = 39 ├Ч (net gain) + (full climb).
  3. X = 39 ├Ч 5 + 6 = 201 cm; Y = 39 ├Ч 4 + 7 = 163 cm; Z = 39 ├Ч 4.5 + 6.5 = 182 cm.
  4. Shortest pillar = 163 cm (Y).
  5. Check for Y: after 38 chances B is at 152 cm and reaches only 159 cm in the 39th climb, so it truly needs the 40th.

Remember ┬╖ Climb-and-slip problems: the last climb has no slip. Height = (n тИТ 1) ├Ч net gain + one full climb.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдЧреЛрдкрд╛рд▓ рдиреЗ рдПрдХ рд╕реЗрд▓ рдлреЛрди рдЦрд░реАрджрд╛ рдФрд░ рдЙрд╕реЗ 10% рд▓рд╛рдн рд▓реЗрдХрд░ рд░рд╛рдо рдХреЛ рдмреЗрдЪ рджрд┐рдпрд╛ред рдмрд╛рдж рдореЗрдВ, рд░рд╛рдо рдЙрд╕реЗ рд╡рд╛рдкрд╕ рдЧреЛрдкрд╛рд▓ рдХреЛ 10% рд╣рд╛рдирд┐ рдЙрдард╛рдХрд░ рдмреЗрдЪ рджреЗрдирд╛ рдЪрд╛рд╣рддрд╛ рд╣реИред рдпрджрд┐ рдЧреЛрдкрд╛рд▓ рдЗрд╕рдХреЗ рд▓рд┐рдП рд╕рд╣рдордд рд╣реЛ, рддреЛ рдЙрд╕рдХреА рд╕реНрдерд┐рддрд┐ рдХреНрдпрд╛ рд╣реЛрдЧреА?

Read this question in English

Gopal bought a cell phone and sold it to Ram at 10% profit. Then Ram wanted to sell it back to Gopal at 10% loss. What will be GopalтАЩs position if he agreed?

(a) Neither loss nor gain ┬╖ (b) Loss 1% ┬╖ (c) Gain 1% ┬╖ (d) Gain 0.5%

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (c) рд▓рд╛рдн 1%

Take Gopal's cost as тВ╣100. Ram pays тВ╣110 and offers the phone back at 10% less, тВ╣99 тАФ тВ╣1 below what Gopal first paid, a 1% gain. UPSC's options compare this buy-back price with Gopal's original cost.

  1. Let Gopal's cost be тВ╣100.
  2. Sold to Ram at 10% profit: тВ╣110.
  3. Ram sells it back at 10% loss on his cost: 110 ├Ч 0.9 = тВ╣99.
  4. Gopal gets back for тВ╣99 the phone that first cost him тВ╣100: a gain of тВ╣1 on тВ╣100 = 1%.
  5. Note: counting both deals, Gopal ends тВ╣11 ahead (+110 тИТ 99); no option matches that, so the options measure only the buy-back price against his original cost.

Remember ┬╖ A rise of x% then a fall of x% leaves the price x┬▓/100 % below the start: 10% up, 10% down тЖТ 1% lower.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдорд╛рди рд▓реАрдЬрд┐рдП рдХрд┐ 9 рд╡реНрдпрдХреНрддрд┐рдпреЛрдВ рдХрд╛ рдФрд╕рдд рд╡рдЬрди 50 kg рд╣реИред рдкреНрд░рдердо 5 рд╡реНрдпрдХреНрддрд┐рдпреЛрдВ рдХрд╛ рдФрд╕рдд рд╡рдЬрди 45 kg рд╣реИ, рдЬрдмрдХрд┐ рдЕрдВрддрд┐рдо 5 рд╡реНрдпрдХреНрддрд┐рдпреЛрдВ рдХрд╛ рдФрд╕рдд рд╡рдЬрди 55 kg рд╣реИред рдкрд╛рдБрдЪрд╡реЗрдВ рд╡реНрдпрдХреНрддрд┐ рдХрд╛ рд╡рдЬрди рд╣реЛрдЧрд╛

Read this question in English

Suppose the average weight of 9 persons is 50 kg. The average weight of the first 5 persons is 45 kg, whereas the average weight of the last 5 persons is 55 kg. Then the weight of the 5th person will be

(a) 45 kg ┬╖ (b) 47.5 kg ┬╖ (c) 50 kg ┬╖ (d) 52.5 kg

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (c) 50 kg

The first five and the last five together cover all nine persons, with the 5th person counted twice. So the 5th person's weight = (5 ├Ч 45 + 5 ├Ч 55) тИТ 9 ├Ч 50 = 500 тИТ 450 = 50 kg.

  1. Total of 9 persons = 9 ├Ч 50 = 450 kg.
  2. First 5 = 5 ├Ч 45 = 225 kg; last 5 = 5 ├Ч 55 = 275 kg.
  3. 225 + 275 = 500 kg, which counts the 5th person twice.
  4. 5th person = 500 тИТ 450 = 50 kg.

Remember ┬╖ When two overlapping groups together cover everyone, (sum of the groups) тИТ (grand total) = the overlap.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

P = (A рдХрд╛ 40%) + (B рдХрд╛ 65%) рддрдерд╛ Q = (A рдХрд╛ 50%) + (B рдХрд╛ 50%) рдЬрд╣рд╛рдБ A, B рд╕реЗ рдмрдбрд╝рд╛ рд╣реИред

рдЗрд╕ рд╕рдиреНрджрд░реНрдн рдореЗрдВ рдирд┐рдореНрдирд▓рд┐рдЦрд┐рдд рдореЗрдВ рд╕реЗ рдХреМрди-рд╕рд╛ рдХрдерди рд╕рд╣реА рд╣реИ?

Read this question in English

P = (40% of A) + (65% of B) and Q = (50% of A) + (50% of B), where A is greater than B.

In this context, which of the following statements is correct?

(a) P is greater than Q. ┬╖ (b) Q is greater than P. ┬╖ (c) P is equal to Q. ┬╖ (d) None of the above can be concluded with certainty.

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (d) рдЙрдкрд░реНрдпреБрдХреНрдд рдореЗрдВ рд╕реЗ рдХреЛрдИ рднреА рдирд┐рд╖реНрдХрд░реНрд╖ рдирд┐рд╢реНрдЪрд┐рдд рд░реВрдк рд╕реЗ рдирд╣реАрдВ рдирд┐рдХрд╛рд▓рд╛ рдЬрд╛ рд╕рдХрддрд╛ред

P тИТ Q = 0.15B тИТ 0.10A, and its sign depends on how much bigger A is than B. If A is less than 1.5 times B, P is larger; if more, Q is larger; at exactly 1.5 times they are equal. So nothing can be concluded.

  1. P тИТ Q = (0.40A + 0.65B) тИТ (0.50A + 0.50B) = 0.15B тИТ 0.10A.
  2. P > Q when 0.15B > 0.10A, i.e. A < 1.5B; Q > P when A > 1.5B; P = Q when A = 1.5B.
  3. A > B allows all three: A = 1.2, B = 1 gives P > Q; A = 3, B = 1 gives Q > P; A = 1.5, B = 1 gives P = Q.
  4. So the comparison cannot be fixed.

Remember ┬╖ Subtract the two expressions and study the sign; if it depends on a ratio the question does not fix, the answer is 'cannot be determined'.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдХрд┐рд╕реА рд╢рд╣рд░ рдореЗрдВ 12% рдкрд░рд┐рд╡рд╛рд░ рдПрдХ рд╡рд░реНрд╖ рдореЗрдВ тВ╣ 30,000 рд╕реЗ рдХрдо рдХрдорд╛рддреЗ рд╣реИрдВ, 6% рдкрд░рд┐рд╡рд╛рд░ рдПрдХ рд╡рд░реНрд╖ рдореЗрдВ тВ╣ 2,00,000 рд╕реЗ рдЕрдзрд┐рдХ рдХрдорд╛рддреЗ рд╣реИрдВ, 22% рдкрд░рд┐рд╡рд╛рд░ рдПрдХ рд╡рд░реНрд╖ рдореЗрдВ тВ╣ 1,00,000 рд╕реЗ рдЕрдзрд┐рдХ рдХрдорд╛рддреЗ рд╣реИрдВ рддрдерд╛ 990 рдкрд░рд┐рд╡рд╛рд░ рдПрдХ рд╡рд░реНрд╖ рдореЗрдВ тВ╣ 30,000 рд╕реЗ тВ╣ 1,00,000 рдХреЗ рдмреАрдЪ рдХрдорд╛рддреЗ рд╣реИрдВред рдХрд┐рддрдиреЗ рдкрд░рд┐рд╡рд╛рд░ рдПрдХ рд╡рд░реНрд╖ рдореЗрдВ тВ╣ 1,00,000 рд╕реЗ тВ╣ 2,00,000 рдХреЗ рдмреАрдЪ рдХрдорд╛рддреЗ рд╣реИрдВ?

Read this question in English

In a city, 12% of households earn less than тВ╣ 30,000 per year, 6% households earn more than тВ╣ 2,00,000 per year, 22% households earn more than тВ╣ 1,00,000 per year and 990 households earn between тВ╣ 30,000 and тВ╣ 1,00,000 per year. How many households earn between тВ╣ 1,00,000 and тВ╣ 2,00,000 per year?

(a) 250 ┬╖ (b) 240 ┬╖ (c) 230 ┬╖ (d) 225

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) 240

The 22% earning above тВ╣1,00,000 includes the 6% above тВ╣2,00,000, so 16% earn between тВ╣1,00,000 and тВ╣2,00,000. The 990 households between тВ╣30,000 and тВ╣1,00,000 are the remaining 66%, which makes 1500 households in all; 16% of 1500 = 240.

  1. Above тВ╣1,00,000: 22%. Below тВ╣30,000: 12%. So тВ╣30,000тАУтВ╣1,00,000: 100 тИТ 22 тИТ 12 = 66%.
  2. 66% = 990 households, so the total = 990 ├╖ 0.66 = 1500.
  3. тВ╣1,00,000тАУтВ╣2,00,000: 22% тИТ 6% = 16% (the 22% already includes the 6% above тВ╣2,00,000).
  4. 16% of 1500 = 240.

Remember ┬╖ 'More than X' groups are cumulative; subtract the higher band to get the slab in between before converting to numbers.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рджреВрдз рдХреЗ рдПрдХ рдирдореВрдиреЗ рдореЗрдВ 50% рдкрд╛рдиреА рд╣реИред рдпрджрд┐ рдЗрд╕ рджреВрдз рдХрд╛ 1/3 рднрд╛рдЧ рдЗрддрдиреА рд╣реА рдорд╛рддреНрд░рд╛ рдХреЗ рд╢реБрджреНрдз рджреВрдз рдореЗрдВ рдорд┐рд▓рд╛рдпрд╛ рдЬрд╛рдП, рддреЛ рдирдП рдорд┐рд╢реНрд░рдг рдореЗрдВ рдкрд╛рдиреА рдХреА рдорд╛рддреНрд░рд╛ рдХрд┐рддрдиреЗ рдкреНрд░рддрд┐рд╢рдд рддрдХ рдХрдо рд╣реЛ рдЬрд╛рдПрдЧреА?

Read this question in English

There is a milk sample with 50% water in it. If 1/3rd of this milk is added to equal amount of pure milk, then water in the new mixture will fall down to

(a) 25% ┬╖ (b) 30% ┬╖ (c) 35% ┬╖ (d) 40%

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (a) 25%

Take the one-third portion as 1 litre: it holds 0.5 litre of water. Adding 1 litre of pure milk makes 2 litres with the same 0.5 litre of water, which is 25%.

  1. Let the portion taken (1/3rd of the sample) be 1 litre; at 50% water it has 0.5 litre of water.
  2. Add an equal amount (1 litre) of pure milk, which has no water: total 2 litres.
  3. Water = 0.5 ├╖ 2 = 25%.

Remember ┬╖ Adding an equal amount of the pure component halves the concentration; the size of the portion taken does not matter.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдПрдХ рдорд╛рд▓рдЧрд╛рдбрд╝реА рджрд┐рд▓реНрд▓реА рд╕реЗ рдореБрдВрдмрдИ рдХреЗ рд▓рд┐рдП 40 km рдкреНрд░рддрд┐ рдШрдВрдЯреЗ рдХреА рдФрд╕рдд рдЪрд╛рд▓ рд╕реЗ рд░рд╡рд╛рдирд╛ рд╣реЛрддреА рд╣реИред рдЙрд╕рдХреЗ рджреЛ рдШрдВрдЯреЗ рдкрд╢реНрдЪрд╛рддреН рдПрдХ рдПрдХреНрд╕рдкреНрд░реЗрд╕ рдЧрд╛рдбрд╝реА рджрд┐рд▓реНрд▓реА рд╕реЗ рдореБрдВрдмрдИ рдХреЗ рд▓рд┐рдП, рдкрд╣рд▓реЗ рд░рд╡рд╛рдирд╛ рд╣реБрдИ рдорд╛рд▓рдЧрд╛рдбрд╝реА рдХреЗ рд╕рдорд╛рдВрддрд░ рдкрде рдкрд░, 60 km рдкреНрд░рддрд┐ рдШрдВрдЯреЗ рдХреА рдФрд╕рдд рдЪрд╛рд▓ рд╕реЗ рд░рд╡рд╛рдирд╛ рд╣реЛрддреА рд╣реИред рджрд┐рд▓реНрд▓реА рд╕реЗ рдХрд┐рддрдиреА рджреВрд░реА рдкрд░ рдПрдХреНрд╕рдкреНрд░реЗрд╕ рдЧрд╛рдбрд╝реА, рдорд╛рд▓рдЧрд╛рдбрд╝реА рд╕реЗ рдорд┐рд▓реЗрдЧреА?

Read this question in English

A freight train left Delhi for Mumbai at an average speed of 40 km/hr. Two hours later, an express train left Delhi for Mumbai, following the freight train on a parallel track at an average speed of 60 km/hr. How far from Delhi would the express train meet the freight train?

(a) 480 km ┬╖ (b) 260 km ┬╖ (c) 240 km ┬╖ (d) 120 km

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (c) 240 km

The freight train has an 80 km lead when the express starts. The express closes the gap at 20 km/h, taking 4 hours, by which time it has run 60 ├Ч 4 = 240 km from Delhi.

  1. Lead of the freight train when the express starts = 40 ├Ч 2 = 80 km.
  2. Relative speed = 60 тИТ 40 = 20 km/h, so time to catch up = 80 ├╖ 20 = 4 h.
  3. Distance of the express from Delhi = 60 ├Ч 4 = 240 km.
  4. Check: the freight train has run 40 ├Ч 6 = 240 km in 6 hours.

Remember ┬╖ Catch-up time = head start ├╖ relative speed; then distance = the chaser's speed ├Ч that time.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

P, Q рдХреА рддреБрд▓рдирд╛ рдореЗрдВ рддреАрди рдЧреБрдирд╛ рддреЗрдЬреА рд╕реЗ рдХрд╛рд░реНрдп рдХрд░рддрд╛ рд╣реИ, рдЬрдмрдХрд┐ P рдФрд░ Q рдПрдХ рд╕рд╛рде рдорд┐рд▓рдХрд░ R рдХреА рддреБрд▓рдирд╛ рдореЗрдВ рдЪрд╛рд░ рдЧреБрдирд╛ рддреЗрдЬреА рд╕реЗ рдХрд╛рд░реНрдп рдХрд░ рд╕рдХрддреЗ рд╣реИрдВред рдпрджрд┐ P, Q рдФрд░ R рдПрдХ рд╕рд╛рде рдорд┐рд▓рдХрд░ рдХрд┐рд╕реА рдХрд╛рд░реНрдп рдХреЛ рдХрд░рддреЗ рд╣реИрдВ, рддреЛ рдЙрдиреНрд╣реЗрдВ рдЖрдкрд╕ рдореЗрдВ рдЕрдкрдиреА рдЖрдп рдХреЛ рдХрд┐рд╕ рдЕрдиреБрдкрд╛рдд рдореЗрдВ рдмрд╛рдБрдЯрдиреА рдЪрд╛рд╣рд┐рдП?

Read this question in English

P works thrice as fast as Q, whereas P and Q together can work four times as fast as R. If P, Q and R together work on a job, in what ratio should they share the earnings?

(a) 3: 1: 1 ┬╖ (b) 3: 2: 4 ┬╖ (c) 4: 3: 4 ┬╖ (d) 3: 1: 4

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (a) 3 : 1 : 1

Working together for the same time, each person's share of the earnings follows his rate of work. With P = 3Q and P + Q = 4R, we get 4Q = 4R, so R = Q and the ratio is 3 : 1 : 1.

  1. Let Q's rate be 1 unit a day; then P's rate = 3.
  2. P + Q = 4 = 4 ├Ч R's rate, so R's rate = 1.
  3. Working for the same time, their shares follow their rates: P : Q : R = 3 : 1 : 1.

Remember ┬╖ When people work together for the same time, split the earnings in the ratio of their work rates.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдХрд┐рд╕реА рд╢рд╣рд░ рдореЗрдВ рдкрд╣рд▓реЗ рдЪрд╛рд░ рджрд┐рди рдФрд╕рдд рд╡рд░реНрд╖рд╛ 0┬╖40 рдЗрдВрдЪ рджрд░реНрдЬ рдХреА рдЧрдИред рдЖрдЦрд┐рд░реА рджреЛ рджрд┐рди 4 : 3 рдХреЗ рдЕрдиреБрдкрд╛рдд рдореЗрдВ рд╡рд░реНрд╖рд╛ рд╣реБрдИред рдЫрдГ рджрд┐рдиреЛрдВ рдХреА рдФрд╕рдд рд╡рд░реНрд╖рд╛ 0┬╖50 рдЗрдВрдЪ рдереАред рдкрд╛рдБрдЪрд╡реЗрдВ рджрд┐рди рдХрд┐рддрдиреА рд╡рд░реНрд╖рд╛ рд╣реБрдИ?

Read this question in English

The average rainfall in a city for the first four days was recorded to be 0.40 inch. The rainfall on the last two days was in the ratio of 4: 3. The average of six days was 0.50 inch. What was the rainfall on the fifth day?

(a) 0.60 inch ┬╖ (b) 0.70 inch ┬╖ (c) 0.80 inch ┬╖ (d) 0.90 inch

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (c) 0┬╖80 рдЗрдВрдЪ

The six days total 6 ├Ч 0.50 = 3.00 inches and the first four days 4 ├Ч 0.40 = 1.60 inches, so the last two days had 1.40 inches. Split in the ratio 4 : 3, the fifth day had 1.40 ├Ч 4/7 = 0.80 inch.

  1. Total for six days = 6 ├Ч 0.50 = 3.00 inches.
  2. Total for the first four days = 4 ├Ч 0.40 = 1.60 inches.
  3. Last two days = 3.00 тИТ 1.60 = 1.40 inches.
  4. Fifth day : sixth day = 4 : 3, so the fifth day = 1.40 ├Ч 4/7 = 0.80 inch.
  5. Check: sixth day = 0.60 inch, and 1.60 + 0.80 + 0.60 = 3.00.

Remember ┬╖ Turn averages into totals first, then split the remaining total in the given ratio.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

X рдФрд░ Y рдХреА рдорд╛рд╕рд┐рдХ рдЖрдп 4 : 3 рдХреЗ рдЕрдиреБрдкрд╛рдд рдореЗрдВ рд╣реИрдВ рдФрд░ рдЙрдирдХреЗ рдорд╛рд╕рд┐рдХ рд╡реНрдпрдп 3 : 2 рдХреЗ рдЕрдиреБрдкрд╛рдд рдореЗрдВ рд╣реИрдВред рдлрд┐рд░ рднреА, рдЙрдирдореЗрдВ рд╕реЗ рдкреНрд░рддреНрдпреЗрдХ рдкреНрд░рддрд┐рдорд╛рд╣ тВ╣ 6,000 рдХреА рдмрдЪрдд рдХрд░рддрд╛ рд╣реИред рдЙрдирдХреА рдХреБрд▓ рдорд╛рд╕рд┐рдХ рдЖрдп рдХреНрдпрд╛ рд╣реИ?

Read this question in English

The monthly incomes of X and Y are in the ratio of 4: 3 and their monthly expenses are in the ratio of 3: 2. However, each saves тВ╣ 6,000 per month. What is their total monthly income?

(a) тВ╣ 28,000 ┬╖ (b) тВ╣ 42,000 ┬╖ (c) тВ╣ 56,000 ┬╖ (d) тВ╣ 84,000

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (b) тВ╣ 42,000

Let incomes be 4k and 3k and expenses 3m and 2m. Equal savings give 4k тИТ 3m = 3k тИТ 2m, so k = m, and then 4k тИТ 3k = тВ╣6,000 gives k = тВ╣6,000. Total income = 7k = тВ╣42,000.

  1. Incomes: 4k and 3k; expenses: 3m and 2m.
  2. Savings: 4k тИТ 3m = 6000 and 3k тИТ 2m = 6000.
  3. Subtracting: k тИТ m = 0, so m = k. Then 4k тИТ 3k = k = 6000.
  4. Total income = 4k + 3k = 7 ├Ч 6000 = тВ╣42,000.
  5. Check: X earns тВ╣24,000 and spends тВ╣18,000; Y earns тВ╣18,000 and spends тВ╣12,000 тАФ each saves тВ╣6,000.

Remember ┬╖ When both save the same amount, equate the two savings expressions first тАФ it links the two ratio multipliers.

Question and answer: UPSC's official GS Paper II (2017, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдПрдХ рдкреЗрдбрд╝ рдкрд░ рдордзреБрд░рд╕ рд╕реЗ рдкрд░рд┐рдкреВрд░реНрдг рдХреБрдЫ рдлреВрд▓ рд╣реИрдВ рдФрд░ рдХреБрдЫ рдордзреБрдордХреНрдЦрд┐рдпрд╛рдБ рдЙрди рдлреВрд▓реЛрдВ рдкрд░ рдордВрдбрд░рд╛ рд░рд╣реА рд╣реИрдВред рдпрджрд┐ рдПрдХ рдордзреБрдордХреНрдЦреА рдкреНрд░рддреНрдпреЗрдХ рдлреВрд▓ рдкрд░ рдмреИрда рдЬрд╛рдП рддреЛ рдПрдХ рдордзреБрдордХреНрдЦреА рдЫреВрдЯ рдЬрд╛рддреА рд╣реИред рдпрджрд┐ рджреЛ рдордзреБрдордХреНрдЦрд┐рдпрд╛рдБ рдкреНрд░рддреНрдпреЗрдХ рдлреВрд▓ рдкрд░ рдмреИрда рдЬрд╛рдПрдВ рддреЛ рдПрдХ рдлреВрд▓ рдЫреВрдЯ рдЬрд╛рддрд╛ рд╣реИред рдлреВрд▓реЛрдВ рдПрд╡рдВ рдордзреБрдордХреНрдЦрд┐рдпреЛрдВ рдХреА рд╕рдВрдЦреНрдпрд╛ рдХреНрд░рдорд╢рдГ рдХрд┐рддрдиреА рд╣реИ ?

Read this question in English

There are some nectar-filled flowers on a tree and some bees are hovering on it. If one bee lands on each flower, one bee will be left out. If two bees land on each flower, one flower will be left out. The number of flowers and bees respectively are:

(a) 2 and 4 ┬╖ (b) 3 and 2 ┬╖ (c) 3 and 4 ┬╖ (d) 4 and 3

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (c) 3 рдФрд░ 4

One bee per flower leaves a bee over, so bees = flowers + 1. Two per flower leaves a flower empty, so bees = 2 ├Ч (flowers тИТ 1). Together these give 3 flowers and 4 bees.

  1. Let f = flowers and b = bees.
  2. One bee per flower, one bee left: b = f + 1.
  3. Two bees per flower, one flower left: b = 2(f тИТ 1).
  4. f + 1 = 2f тИТ 2, so f = 3 and b = 4.
  5. Check: 4 bees on 3 flowers, one each, leaves 1 bee; two each fills 2 flowers and leaves 1 flower empty.

Remember ┬╖ Turn each 'left over' condition into an equation тАФ or simply test each option against both conditions.

Question and answer: UPSC's official GS Paper II (2016, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдПрдХ рдЧреНрд░рд╛рд╣рдХ рджреНрд╡рд╛рд░рд╛ рдХрд┐рд╕реА рдЦрд╛рд╕ рдЙрддреНрдкрд╛рдж рдХреА 19000 рдорд╛рддреНрд░рд╛ рдХрд╛ рдПрдХ рдХреНрд░рдп-рдЖрджреЗрд╢ рджрд┐рдпрд╛ рдЧрдпрд╛ рд╣реИред рдХрдореНрдкрдиреА рдкреНрд░рддрд┐рджрд┐рди рдЙрд╕ рдЙрддреНрдкрд╛рдж рдХреА 1000 рдорд╛рддреНрд░рд╛ рдЙрддреНрдкрд╛рджрд┐рдд рдХрд░рддреА рд╣реИ рдЬрд┐рд╕рдореЗрдВ рд╕реЗ 5% рдмрд┐рдХреНрд░реА рдХреЗ рдЕрдиреБрдкрдпреБрдХреНрдд рд╣реЛрддреА рд╣реИред рдХреНрд░рдп-рдЖрджреЗрд╢ рдХрд┐рддрдиреЗ рджрд┐рдиреЛрдВ рдореЗрдВ рдкреВрд░рд╛ рд╣реЛрдЧрд╛ ?

Read this question in English

There is an order of 19000 quantity of a particular product from a customer. The firm produces 1000 quantity of that product per day out of which 5% are unfit for sale. In how many days will the order be completed?

(a) 18 ┬╖ (b) 19 ┬╖ (c) 20 ┬╖ (d) 22

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (c) 20

Only 95% of each day's 1000 units can be sold, which is 950 units a day. The order of 19000 therefore takes 19000 ├╖ 950 = 20 days.

  1. Usable output per day = 95% of 1000 = 950.
  2. Days needed = 19000 ├╖ 950 = 20.
  3. Check: 20 ├Ч 950 = 19000.

Remember ┬╖ Divide the order by the usable output per day, not the gross output.

Question and answer: UPSC's official GS Paper II (2016, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдПрдХ рдХрдХреНрд╖рд╛ рдкреВрд░реНрд╡рд╛рд╣реНрди 11:00 рдмрдЬреЗ рдкреНрд░рд╛рд░рдВрдн рд╣реЛрддреА рд╣реИ рдФрд░ рдЕрдкрд░рд╛рд╣реНрди 2:27 рдмрдЬреЗ рд╕рдорд╛рдкреНрдд рд╣реЛрддреА рд╣реИред рдЗрд╕ рдЕрдВрддрд░рд╛рд▓ рдореЗрдВ рдЪрд╛рд░ рд╕рдорд╛рди рдЕрд╡рдзрд┐ рдХреЗ рдкреАрд░рд┐рдпрдб рд╣реЛрддреЗ рд╣реИрдВред рдкреНрд░рддреНрдпреЗрдХ рдкреАрд░рд┐рдпрдб рдХреЗ рдмрд╛рдж рдЫрд╛рддреНрд░реЛрдВ рдХреЛ 5 рдорд┐рдирдЯ рдХрд╛ рд╡рд┐рд╢реНрд░рд╛рдо рджрд┐рдпрд╛ рдЬрд╛рддрд╛ рд╣реИред рдкреНрд░рддреНрдпреЗрдХ рдкреАрд░рд┐рдпрдб рдХреА рдареАрдХ-рдареАрдХ рдЕрд╡рдзрд┐ рдХрд┐рддрдиреА рд╣реИ ?

Read this question in English

A class starts at 11:00 am and lasts till 2:27 pm. Four periods of equal duration are held during this interval. After every period, a rest of 5 minutes is given to the students. The exact duration of each period is:

(a) 48 minutes ┬╖ (b) 50 minutes ┬╖ (c) 51 minutes ┬╖ (d) 53 minutes

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (a) 48 рдорд┐рдирдЯ

The class lasts 207 minutes. Four periods have three 5-minute rests between them, since the last period ends the class, so each period is (207 тИТ 15) ├╖ 4 = 48 minutes.

  1. 11:00 am to 2:27 pm = 3 h 27 min = 207 minutes.
  2. Four periods have three rests between them: 3 ├Ч 5 = 15 minutes.
  3. Teaching time = 207 тИТ 15 = 192 minutes; each period = 192 ├╖ 4 = 48 minutes.
  4. Check: 48 + 5 + 48 + 5 + 48 + 5 + 48 = 207.

Remember ┬╖ n periods in a block have n тИТ 1 breaks between them: subtract the breaks, then divide by n.

Question and answer: UPSC's official GS Paper II (2016, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

рдкрд╛рддреНрд░ A рдореЗрдВ 30 рдЧреНрд░рд╛рдо рд╢рд░реНрдХрд░рд╛ рдХреЛ 180 рдорд┐.рд▓реА. рдЬрд▓ рдореЗрдВ рдорд┐рд▓рд╛рдпрд╛ рдЧрдпрд╛, рдкрд╛рддреНрд░ B рдореЗрдВ 40 рдЧреНрд░рд╛рдо рд╢рд░реНрдХрд░рд╛ рдХреЛ 280 рдорд┐.рд▓реА. рдЬрд▓ рдореЗрдВ рдорд┐рд▓рд╛рдпрд╛ рдЧрдпрд╛ рдФрд░ рдкрд╛рддреНрд░ C рдореЗрдВ 20 рдЧреНрд░рд╛рдо рд╢рд░реНрдХрд░рд╛ рдХреЛ 100 рдорд┐.рд▓реА. рдЬрд▓ рдореЗрдВ рдорд┐рд▓рд╛рдпрд╛ рдЧрдпрд╛ред рдкрд╛рддреНрд░ B рдХрд╛ рд╡рд┐рд▓рдпрди рдХреИрд╕рд╛ рд╣реИ ?

Read this question in English

30 g of sugar was mixed in 180 ml water in a vessel A, 40 g of sugar was mixed in 280 ml of water in vessel B and 20 g of sugar was mixed in 100 ml of water in vessel C. The solution in vessel B is:

(a) sweeter than that in C ┬╖ (b) sweeter than that in A ┬╖ (c) as sweet as that in C ┬╖ (d) less sweet than that in C

рдЙрддреНрддрд░ рдФрд░ рд╡реНрдпрд╛рдЦреНрдпрд╛ ┬╖ explanation in English

Answer: (d) C рдХреЗ рд╡рд┐рд▓рдпрди рд╕реЗ рдХрдо рдореАрдард╛

Sweetness depends on sugar per unit of water. A has 30/180 = 1/6, B has 40/280 = 1/7 and C has 20/100 = 1/5 g per ml, so B is the weakest and is less sweet than C.

  1. Sugar per ml of water тАФ A: 30/180 = 1/6; B: 40/280 = 1/7; C: 20/100 = 1/5.
  2. 1/7 < 1/6 < 1/5, so B is the least sweet of the three.
  3. So B is less sweet than C (and than A); (a), (b) and (c) are false.

Remember ┬╖ Compare concentrations as ratios; reducing each to a simple fraction (1/5, 1/6, 1/7) makes the order obvious.

Question and answer: UPSC's official GS Paper II (2016, Series A) тАФ paper тЖЧ ┬╖ answer key тЖЧ. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). Permalink ┬╖

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  • HighPercentages, profit & loss ┬╖ 33 questions
  • HighAverages & ages ┬╖ 19 questions

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