試題詳解

90. A store has 80 modems in its inventory, 30 coming from Source A and the remainder from Source B. Of the modems in inventory from Source A, 20% are defective. Of the modems in inventory from Source B, 8% are defective.
Calculate the probability that exactly two out of a sample of five modems selected without replacement from the store’s inventory are defective.
(A) 0.010
(B) 0.078
(C) 0.102
(D) 0.105
(E) 0.125