Question

In a certain college, $25\%$ of boys and $10\%$ of girls are studying mathematics. The girls Constitution $60\%$ of the student body.If a student is selected at random and is found to be studying mathematics, the probability that the student is a girl is.

Answer 1

Let $100$ students studying in which $60$ % girls and $40$ % boys.

No. of boys $=40,$ No. of girls $=60$

$25$% of boys offer Maths

$=\frac{25}{100}\times 40=10$ Boys

$10$% of girls offer Maths

$=\frac{10}{100}\times 40=10$ Girls

It means $16$ students offer Maths.

The required probability that the random person selected is a girl $=\frac{6}{16}.$