A die is rolled . If the outcome is an odd number what is the probability that it is prime ?

Options

A. `(2)/(3)`
B. `(3)/(4)`
C. `(5)/(12)`
D. none of these

Answer

A

Explanation

Here `S={1,2,3,4,5,6}`
Let `A ={1,2,3,5,},B={2,3,5}` Then `A nnB ={3,5}`
`:. P(A)=(3)/(6)=(1)/(2),P(B) =(3)/(6)=(1)/(2) "and " P(A nn B) =(2)/(6)=(1)/(3)`
` :. P(B//A) =(P(A nnB))/(P(A)) =(((1)/(3)))/(((1)/(2))) =(2)/(3)`