Question
Two balls are drawn at random with replacement from a box containing 10 black and 8 red balls. Find the probability that one of them is black and other is red.
Solution
Number of black balls = 10
Number of red balls = 8
Total number of balls = 10 + 8 = 18
P(one of them is black and other red) = P(BR) + P(RB) = P(B) P(R) + P(R) P(B)
