In how many ways can a committee of 4 be selected from a group of 12 people?

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1 Answer

495

Explanation:

We don't care about the order in which people are picked and so this is a combinations question:

#C_(n,k)=((n),(k))=(n!)/((k!)(n-k)!)# with #n="population", k="picks"#

#((12),(4))=495#

For anyone who doesn't have Pascal's Triangle saved as a wallpaper, we can work it the long way:

#(12!)/((4!)(8!))=(12xx11xx10xx9)/24=495#