Question

In how many ways can 3 things be chosen from a group of 10 (where order doesn't matter)?

Answer 1

120

Explanation:

Since order doesn't matter, this is a combinations question.

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

`C_(10,3)=(10!)/((3!)(7!))=(10xx9xx8xx7!)/(6xx7!)=120`