A bag has 6 black balls, 4 red balls and 8 white balls. If two balls are drawn at random, then find the probability that it contains no black balls

A bag has 6 black balls, 4 red balls and 8 white balls. If two balls are drawn at random, then find the probability that it contains no black balls.

a) 5/8

b) 4/91

c) 1/33

d) 22/51

e) None of these

Sol:

Number of Non black balls = 4 + 8 = 12

Required probability =12c2/18c2= (12*11) / (18 *

17) = 22 /51