A box contains nine light out of which 4 are defective. If four light are chosen at random, find the probability that all the four light are defective?  Pick:
A) 2/113 B) 3/121 C) 1/126 D) 3/101 E) None of these
Out of nine light , five are good and four are defective.   Required probability = ⁴1/126₄/⁹1/126₄ = 1/126   1/126
<result>C</result>
A box contains nine light out of which 4 are defective. If four light are chosen at random, find the probability that all the four light are defective?