It has two parts to this problem. You are given $n$ and $k$. You have to tell the minimum number of pieces, $a$, you can cut a sandwich of length $n$ such that the length of no piece is greater than $k$. The answer is quite simple, isn’t it ? Answer of the first part click to hide $a = \lceil \frac{n}{k} \rceil$ The second part is, how many ways we can cut the sandwich into $a$ pieces such that the length of no piece is greater than $k$.