Question

A box contains 12 plastic forks and 6 plastic knives. If two utensils are chosen at random from the box without replacement, what is the probability that they are different?

A)
13
17
B)
4
17
C)
8
17
D)
9
17

Answer 1

817

P(fork and knife) = P(fork) x P(knife|fork) = 1218 x 617 = 417

P(knife and fork) = P(knife) x P(fork|knife) = 618 x 1217 = 417

P(different utensils) = 417 + 417 = 817