# stuck on more probability

• Feb 26th 2009, 01:27 PM
johnewton
stuck on more probability
Much appreciated in advance for guidance on this..

A sample of 5 different calculators is randomly selected from a group containing 16 that are defective and 30 that have no defects.

(a) What is the probability that 3 of the 5 calculators in the sample are defective?

(b) What is the probability that at least one of the 5 calculators in the sample is defective?
• Feb 26th 2009, 02:22 PM
Plato
Quote:

Originally Posted by johnewton
A sample of 5 different calculators is randomly selected from a group containing 16 that are defective and 30 that have no defects.
(b) What is the probability that at least one of the 5 calculators in the sample is defective?

The probability that none of the five is defective is: $\Large{ \frac{{30\choose 5}}{{46\choose 5}}}$.