In a class 40 % students read Mathematics, 25 % Biology and 15% both Mathematics and Biology. One student is selected at random. The probability that he reads Mathematics if it is known that he reads Biology is

Options

A. `(2)/(5)`
B. `(3)/(5)`
C. `(3)/(8)`
D. `(5)/(8)`

Answer

B

Explanation

Let A= event of reading mathematics and B of reading biology.
`P(A)=(60)/(100)=(3)/(5) ,P(B) =(25)/(100)=(1)/(4) " and " P(A nnB) =(15)/(100)=(3)/(20)`
`:.P(A//B) =(P(A nn B))/(P(B)) =((3)/(20)xx (4)/(1)) =(3)/(5)`