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?
Answer & explanation
Answer: (c) 0.80 inch
The six days total 6 × 0.50 = 3.00 inches and the first four days 4 × 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 × 4/7 = 0.80 inch.
- Total for six days = 6 × 0.50 = 3.00 inches.
- Total for the first four days = 4 × 0.40 = 1.60 inches.
- Last two days = 3.00 − 1.60 = 1.40 inches.
- Fifth day : sixth day = 4 : 3, so the fifth day = 1.40 × 4/7 = 0.80 inch.
- 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) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·