Question

A bag contains 12 balls out of which x are white.
(1) if one ball is drawn at random, what is the probability that it will be a white ball ?
(2) if 6 more white balls are put in the bag, the probability of drawing a white ball will be double than that in
(1)find x.

Answer 1

probability of getting the white balls is equal to X /12
x is equal to 12 - x is equal to 12 minus 6 is equal to 6

Answer 2

1) the probability is x/12

2) the probability is
x+6/12+6
= x+6/18


2(x/12) = x+6/18

2x/12 = x+6/18
2x /2 = x+6/3
3x = x+6
2x = 6
x = 3