Answer
See below.
Work Step by Step
If we want to choose $k$ elements out of $n$ regarding the order, not allowing repetition, we can do this in $_{n}P_k=\frac{n!}{(n-k)!}$ ways.
So e.g. if we have a competition where $7$ people take part, then the number of possibilities for the order of the top $3$ contestants is $_7P_3$.
