Good practice to divide items into groups

1. How many ways can 10 people be divided into 2 groups?
2. What is division into groups?

How many ways can 10 people be divided into 2 groups?

Therefore, there are 511 possible ways of creating two groups from 10 people.

What is division into groups?

Number of ways of dividing m+n (where m ≠ n) things into two unequal groups of size m and n is ^m+nC_m × ⁿC_n = (m+n)!/m! n!. 2. Number of ways of dividing (m+n+p) (where m ≠ n ≠ p) things into 3 unequal groups of size m, n, p is given by (m+n+p)!/m!