A box contains nine bulbs out of which 4 are defective. If four bulbs are chosen at random, find the probability that all the four bulbs are defective?	Choose the most appropriate option
A) 1/129  B) 1/199  C) 1/122  D) 1/121  E) 1/126
Out of nine, five are good and four are defective. Required probability   = 4C4/9C4 = 1/126   Answer:1/126
<result>E</result>
A box contains nine bulbs out of which 4 are defective. If four bulbs are chosen at random, find the probability that all the four bulbs are defective?