UPSC Prelims 2000·GS1·polity-and-governance·social justice and international relations

In a class there are 18 boys who are over 160 cm tall. If these boys constitute three fourths of the boys and the total number of boys is two third of the number of students in the class, then what is the number of girls in the class?

Dalvoy logo
Reviewed by Dalvoy
UPSC Civil Services preparation
Last updated 8 Jul 2026, 4:39 pm IST
  1. A6
  2. B12Correct
  3. C18
  4. D24

Explanation

Here is the step by step breakdown of the solution:

Step 1: Find the total number of boys. We are told that 18 boys represent three fourths of the total boys. To find the total number of boys, we divide 18 by 3 and multiply by 4. 18 divided by 3 is 6. 6 multiplied by 4 is 24. So, there are 24 boys in total.

Step 2: Find the total number of students in the class. The problem states that the total number of boys is two thirds of the total number of students. To find the total students, we divide 24 by 2 and multiply by 3. 24 divided by 2 is 12. 12 multiplied by 3 is 36. So, there are 36 students in total.

Step 3: Find the number of girls. The number of girls is the total students minus the total boys. 36 total students minus 24 boys equals 12 girls.

Therefore, the number of girls in the class is 12. The correct option is B.

polity-and-governance: In a class there are 18 boys who are over 160 cm tall. If these boys constitute three fourths of the boys and the total
ShareWhatsAppXTelegram

Related questions

More UPSC Prelims practice from the same subject and topic.