The average monthly income of a person in a certain family of 5 is Rs. 10,000. What will be the average monthly income of a person in the same family if the income of one person increased by Rs. 1,20,000 per year?
Answer & explanation
Answer: (a) Rs. 12,000
A rise of Rs. 1,20,000 a year is Rs. 10,000 a month. Shared across 5 people it lifts the monthly average by Rs. 2,000, from Rs. 10,000 to Rs. 12,000.
- Family's monthly income = 5 × Rs. 10,000 = Rs. 50,000.
- Rs. 1,20,000 a year = Rs. 10,000 a month.
- New average = (50,000 + 10,000) ÷ 5 = Rs. 12,000.
Remember · Put all figures in the same time unit first; the average then rises by the increase divided by the number of people.
Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·