Question

A box contains 23 transistors,6 of which are defective. If 6 are selected at random, find the probility that none are defective ?

Answer 1

$|\Omega|=C(23,6)=\dfrac{23!}{6!17!}=100947\\ |A|=C(17,6)=\dfrac{17!}{6!11!}=12376\\\\ P(A)=\dfrac{12376}{100947}=\dfrac{1768}{14421}$