Question

A carton contains 20 shirts , of which q are made of pure cotton. After 4 more pure cotton shirts are added to the carton, the probability of drawing a pure cotton shirt becomes 3/4 , find the value of q.

Answer 1

The value of q = 11

Explanation:

Number of pure cotton shirts =
`(4+q)/(20)`

Probability of drawing pure cotton shirts =
`(4+q)/(20)` =
`(3)/(4)`

Substituting the above problem = 4(4 + q) = 3 x 20

= 16 + 4q = 60

= 4q = 60 - 16 = 44

= q =
`(44)/(4)`

∴ q = 11