Question

If 2 more red balls are put in the bag, the probability of drawing a red ball will be 9/8 times the of probability of red ball coming in part(i). Find the value of x

Answer 1

Answer:

Total No . of Observations = 18

No . of Red Balls = x

Probability of Red Ball = Favourable Observations / Total No. of Observations

P(of Red Ball) = x/18

Two Red Balls Are Added

Updated No . of Red Balls = x + 2

Total no of Balls = 18 + 2 = 20

P(of red Ball) = x + 2 / 20

P(updated red balls) is 9/8 times of P(initial red balls)

9/8 * x/18 = (x + 2)/20

x / 16 = (x + 2)/20

(x / 16) * 20 = x + 2

5x / 4 = x + 2

5x = 4x + 8

5x - 4x = 8

x = 8

Therefore,

Initial No.Of Red Balls = 8