There are $m$ white and $n$ black balls, with $m>n$.

In how many ways can all the balls be arranged in a row so that no two black balls are adjacent?
From $m+1$ positions ( $m-1$ intervals between white balls and two places at the ends), we need to choose $n$ positions, in which black balls will be placed.

## Answer

$C_{m+1}^{n}$ ways.