how many ways can a 3 person committee be formed from 12 people

C(12,3)

= 12!/(3!9!)
= 220

Added attraction:
Google Pascal's triangle
look at the row: 1 12 66 220 495 ....

here is a good one..
http://ptri1.tripod.com/

Two committees, one with six and one with seven people, with no one person serving on both committees at the same time. In how many ways can this be done.

To find the number of ways a 3-person committee can be formed from a group of 12 people, we can use the concept of combinations.

In general, the number of combinations of "n" objects taken "r" at a time is given by the formula:

C(n, r) = n! / (r! * (n-r)!)

where "!" denotes the factorial of a number.

In this case, we want to find the number of combinations of 12 people taken 3 at a time:

C(12, 3) = 12! / (3! * (12-3)!)

Calculating this expression will give us the number of ways a 3-person committee can be formed from a group of 12 people.