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

1 Answer

70

Explanation:

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

Cn,k=n!(k!)(nk)! 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:

C8,4=8!(4!)(4!)=8×7×6×524=70