16. Simplify 6p2

30
15
12
720

17. Simplify 8c5
6,720
336
56
10

Okay, so the formula for Permutations is n!/(n-r)! and the formula for Combinations is
n!/r!(n-r)! however I don't quite know how to figure either of these out. I'm sort of blanking here! Please help.
BTW, Ms. Sue, if "this is not your area," then don't comment on this. That simple.