Question

Find the Probabilities of Given Conditions
A box Contains 2 Red, 3 Black, and 5 White balls, if 3 balls are drawn at random without replacement, find the probabilities: a) 3 balls are Black b) Two are Red & one is Black c) At least one is White.

Answer 1

a)    n(black balls) = 3
       n(S) = 10
       P(3 Black balls) = 3/10

b) n(red balls) = 2 and n(Black balls) = 3
    n( black ball + red balls) = 2+3 = 5
    n(S) = 10
    P(1 black ball + 2 red balls) = 5/10
                                                 = 1/2

c) n(white balls) = 5
    n(S) = 10
    P ( At least one white ball) = 5/10
                                               = 1/2