A box contains ten bulbs out of which 5 are defective. If four bulbs are chosen at random, find the probability that exactly three bulbs are good? Select
A) 5/21  B) 9/21  C) 7/21  D) 6/21  E) 8/21
Required probability = (5C3 . 5C1)/10C4 = (10 * 5)/210   = 5/21   5/21nswer:5/21
<result>A</result>
A box contains ten bulbs out of which 5 are defective. If four bulbs are chosen at random, find the probability that exactly three bulbs are good?