Question

A bag contain 15 balls, out of which some are white and others are black. If the probability of drawing a black ball at random from the bag is 2/3 , then find how many balls are there in the bag

Answer 1

Let us consider no. of black balls to be x, and no. of white balls to be 15-x.

We know that,

x/15 = 2/3

which means no. of black balls = 10.

Therefore no. of white balls = 5.

Hope it helps ;-)