Question

A law firm has ten senior and eleven junior partners. A committee of 8 partners is selected at random to represent the firm at a conference. What is the probability that at least one of the junior partners is on the committee?

Answer 1

The probability that none of the junior partners is selected is given by:
$\frac{10C8}{21C8}=\frac{1}{4522}$
Therefore the probability that at least one junior partner is selected is:
$1-\frac{1}{4522}=\frac{4521}{4522}=0.99978$
The answer is 0.99978