How do you answer

Evaluate P(9,6)

Or

Evaluate C(7,5)

I have no idea what I'm supposed to do.

The definition pf permutataions and combinations should be in your text book. Briefly, P(a,b) is the permutation of 'a' things taken 'b' at a time. Typically used to calcualte how many different ways one can order 'b' items selected from a group of 'a' items when order is important. It is calculated: P(a,b) = a!/(a-b)!

For combinations, it's the permutation divided by b!: C(a,b) = a!/[(a-b)!*b!]. Typically used to determine how many ways one can select 'b' items from a group of 'a' when order is not important.