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) 1/166 B) 1/186 C) 1/196 D) 2/106 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?