Question
When order matters, use the _________________ formula.
Answers
GPT-4o mini
When order matters, use the **permutation** formula. The permutation formula is used to calculate the number of ways to arrange a subset of items from a larger set when the order of arrangement is important. The formula for permutations of \( n \) items taken \( r \) at a time is given by:
\[
P(n, r) = \frac{n!}{(n-r)!}
\]
where \( n! \) (n factorial) is the product of all positive integers up to \( n \).
\[
P(n, r) = \frac{n!}{(n-r)!}
\]
where \( n! \) (n factorial) is the product of all positive integers up to \( n \).