Explanation
Correct option is B)
let the number of boys and girls in the college be 7x and 8x
their increased number is (120% of 7x) =
⇒ $\frac{120}{100}$ ×7x
⇒ $\frac{42x}{5}$
And (110% of 8x) ⇒ $\frac{110}{100}$ × 8x
⇒ $\frac{44x}{5}$
∴Required Ratio = $\frac{42x}{5}$ : $\frac{44x}{5}$
ANSWER = 21:22 i.e. (B) 21:22
