A box contains 25 electric bulbs, out of which 4 are defective. Two bulbs are chosen at random from this box. The probability that at least one of these is defective is Answers:  A) 3/10  B) 7/19  C) 12/19  D) 21/95  E) None
Solution   P( None is defective)   = 21C2 / 25C2   = 7/10   P( at least one is defective)   = (1- 7/10)   =3/10.   3/10nswer 3/10
<result>A</result>
A box contains 25 electric bulbs, out of which 4 are defective. Two bulbs are chosen at random from this box. The probability that at least one of these is defective is