15 A box of parts contains 8 good items and 2 defective item

15. A box of parts contains 8 good items and 2 defective items. If 2 are selected at

random without replacement, - that is, the first item isn\'t replaced before the second is drawn -

find the probability that one is defective and the other isn\'t.

Solution

There are 10C2 ways to choose any 2 items.

There are 8*2 = 16 ways to get 1 defective and one good item.

Thus, the probability of the event described is

P = 16 / (10C2) = 0.355555556 [answer]