# Probability Question related to GMAT

#### kamranlatif

##### New Member
There are a total of 60 white and red balls in the box. A ball in picked randomly. If the probability of picking a white ball is 2/5. How many red balls should be taken out so that the probability of picking white balls becomes 7/9 ?

I am unable to crack this one.

#### asterisk

##### New Member
2/5 * 60 = 24

There are 24 white and 36 red.

Since $$24/X = 7/9$$

does not have an integer solution, you cannot solve this by just removing red balls.

If you remove red and white balls you can have 7/9, 14/18 or 21/27.

(7 white and 2 red) or (14 white and 4 red) or (21 white and 6 red)