Question

A bag contains 18 balls out of which x balls are red
(i) If one ball is drawn at random from the bag what is the probability that it is not red?
(ii) If 2 more red balls are put in the bag the probability drawing a red ball will be 9/8 times the probability of drawing a red ball in the first case. Find the value of x

Answer 1

I) total no of balls =18
red balls= x
pro= 18-x/18
ii) no of red balls =x+2
x+2/20= x/18 × 9/8
4x+8=5x
X=8