In a college, number of boys is 75% of number of girls. Difference between boys and girls is 35. On a particular day 20% boys were absent, then find the number of boys those who present?

In a college, number of boys is 75% of number of girls. Difference between boys and girls is 35. On a particular day 20% boys were absent, then find the number of boys those who present?

A 72

B 84

C 93

D 81

Solution

Correct Answer: Option B

Ratio of girls and boys = 100% : 75% = 4:3

Difference is 1 unit = 35

So, 3 units = 35 x 3 = 105

If 20% absent, that’s mean 80% present.

So, present boys = 80% of 105 = \(\frac{80\times105}{100}\;=\;84\)