Consider the following : Weight of 6 boys = Weight of 7 girls = Weight of 3 men = Weight of 4 women If the average weight of the women is 63 kg, then what is the average weight of the boys?

(a) 40 kg
(b) 42 kg ✓ UPSC's answer
(c) 45 kg
(d) 63 kg

Why the answer is (b)

• Let the total weight of the group be W.

• The problem states that the weight of 4 women is equal to W, so 4 * (Average Weight of Women) = W.

• Given the average weight of women is 63 kg, W = 4 * 63 = 252 kg.

• The weight of 6 boys is also equal to W, so 6 * (Average Weight of Boys) = 252 kg.

• Solving for the average weight of boys: 252 / 6 = 42 kg.

• Therefore, the average weight of the boys is 42 kg, which corresponds to option (b).

Why the other options are wrong

(a) 40 kg: 40 kg is incorrect because 6 * 40 = 240 kg, which does not equal the total weight of 252 kg derived from the women's data.
(c) 45 kg: 45 kg is incorrect because 6 * 45 = 270 kg, which does not equal the total weight of 252 kg derived from the women's data.
(d) 63 kg: 63 kg is incorrect because it is the average weight of the women, not the boys, and 6 * 63 = 378 kg, which is not equal to 252 kg.

Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2024, held on 16 June 2024. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.