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 is not red? (ii) If 2 more red balls are put in the bag, the probability of 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

Answer 2

Answer:

Probability of finding a red ball in a draw- x/18.

i) Probability of not finding a red ball in a draw is 1 - x/18 = (18 - x)/18

ii) If two red balls are put in, then there is 20 balls, out of which x + 2 are red.

Probability of drawing a red ball- (x+2)/20.

According to the question,

Pls view attachment............

So, the answer is x = 8