Word Problem Permutations: Help!

[firstcitizen]

Advertisement - Members don't see this ad

The last time I took algebra was 7th grade and I'm having trouble with applying permutations to word problems.

In which cases would I use:

ex)

a) 5! / 3!2!

b) 5! / (3-2)!

 

[fancymylotus]

I'm sure Streetwolf has explained this ad nauseum.

Order matters: n!/(n-r!) Permutation

Order doesnt matter: n!/[r!(n-r)!] Combination