A sum of Rs. 312 was divided among 100 boys and girls in such a way that each boy gets Rs. 3.60 and each girl Rs. 2.40. Find the number of girls.

Correct option is A

Ans. (a)
Sol.
Let the number of boys = x,
Then number of girls = 100 − x
Each boy gets ₹3.60, each girl gets ₹2.40.
Total amount distributed = ₹312
Now,
3.60x + 2.40(100 − x) = 312
⇒ 3.60x + 240 − 2.40x = 312
⇒ (3.60 − 2.40)x = 312 − 240
⇒ 1.20x = 72
⇒ x = 72 / 1.20 = 60
So, number of girls = 100 − 60 = 40