Type nPr(n, r) for permutations and nCr(n, r) for combinations. Order matters in nPr. It does not in nCr. The two ideas as a set are in permutations versus combinations.
One function, not a factorial wall
nPr(9, 5) and nCr(9, 5) skip the long product. Sum notation is a different leftover, in sum notation.
Desmos as a tool is in Desmos on the ACT.
The bottom line
Order matters: nPr. Order does not: nCr. Type the function.
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