Question

Evaluate 15 P 3 ---- This is counting methods and probability.

Answer 1

15*14*13

Answer 2

Now if their was a different letter in the middle would it effect the problem?

Answer 3

what do you mean by a different letter in the middle

Answer 4

Like 15 C 3

Answer 5

ok, so the basic idea is that "order matters" in combinations, while it doesn't in permutations. So in 15 P 3, 131 and 113 are different, in combinations they're the same

Answer 6

ok thanks

Answer 7

no problem