Ratio of Boys and Girls – UGC NET Question

The ratio 3 : 2 indicates that out of every 5 equal parts, 3 parts represent boys and 2 parts represent girls. The total number of parts is therefore 3 + 2 = 5. If 5 parts correspond to 90 students, then 1 part equals 90 ÷ 5 = 18 students. The number of boys is 3 parts, which is 3 × 18 = 54.

Option A:
Option A, 36, corresponds to 2 parts of 18 instead of 3, which would actually represent the number of girls if the same logic is applied correctly to the ratio. Hence, it mismatches the role of boys in the ratio.

Option B:
Option B, 45, is obtained if someone wrongly assumes 90 × (1/2) but that would correspond to a hypothetical 1 : 1 ratio. It does not respect the actual 3 : 2 proportion given in the question.

Option C:
Option C follows the correct ratio method: convert the total into parts, find the value of one part and then multiply by the number of parts corresponding to boys. This systematic approach yields 54, aligning with the structure of the ratio.

Option D:
Option D, 60, would imply that boys form two thirds of the class, which does not fit a 3 : 2 ratio where boys are 3/5 of the total. It clearly exceeds the value compatible with the defined proportion.