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UPSC CSE CSAT 2021 · Paper II (CSAT) · Question 60 · Number system

निम्नलिखित गुणन (मल्टिप्लिकेशन) के प्रश्न पर विचार कीजिए : (PQ) × 3 = RQQ, जहाँ P, Q और R भिन्न…

UPSC Civil Services (Preliminary) Examination 2021, General Studies Paper II (CSAT), Question 60 — Number system.

CSAT 2021 · Q60

Number system Medium

निम्नलिखित गुणन (मल्टिप्लिकेशन) के प्रश्न पर विचार कीजिए :

(PQ) × 3 = RQQ, जहाँ P, Q और R भिन्न अंक हैं और R ≠ 0 है ।

(P + R) ÷ Q का मान क्या है ?

Read this question in English

Consider the following multiplication problem:

(PQ) × 3 = RQQ, where P, Q and R are different digits and R ≠ 0.

What is the value of (P + R) ÷ Q?

(a) 1 · (b) 2 · (c) 5 · (d) Cannot be determined due to insufficient data

उत्तर और व्याख्या · explanation in English

Answer: (b) 2

Three times Q must end in Q, so Q is 0 or 5, and only Q = 5 works. Then 85 × 3 = 255 is the only fit, so P = 8, R = 2 and (P + R) ÷ Q = 10 ÷ 5 = 2.

  1. The units digit of 3 × Q must be Q, so Q = 0 or 5.
  2. Q = 0: P0 × 3 = R00 needs 30P = 100R, i.e. 3P = 10R — no digit P works with R ≠ 0.
  3. Q = 5: (10P + 5) × 3 = 100R + 55 gives 30P = 100R + 40, i.e. 3P = 10R + 4, so P = 8 and R = 2.
  4. 85 × 3 = 255, and (P + R) ÷ Q = (8 + 2) ÷ 5 = 2.

Remember · In digit puzzles, start with the units place — digits whose multiples end in themselves narrow things quickly.

Question and answer: UPSC's official GS Paper II (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·

Cite this question: UPSC CSE CSAT 2021, Q60 — minimalistias.com/pyqs/csat/2021/q60

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