Question

8 people are divided evenly into 2 groups, find the number of ways to divide them?

Answer 1

70

Explanation:

This is a combination question - we don't care about the order in which people are picked. The combination formula is:

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

We have 8 people and are picking 4 to be in one group (which forces the other people into the other group). That's:

`C_(8,4)=(8!)/((4!)(4!))=(8xx7xx6xx5)/24=70`