Question

There are 12 green balls and (x+2) yellow balls in a box. If the probability of selecting a green ball at random is 2/5, find the value of x.

Answer 1

x = 16

Explanation:

The probability of obtaining a green ball is

P(green) =
`(12)/(12+x+2)` =
`(12)/(x+14)` and

P(green) =
`(2)/(5)`, hence equating gives

`(12)/(x+14)` =
`(2)/(5)` ( cross- multiply )

2(x + 14) = 60 ( divide both sides by 2 )

x + 14 = 30 ( subtract 14 from both sides )

x = 16