Permutation / Computation Guide

parikhs
Thu, 01 Sep 2005 22:05:09 +0000

Hey guys, I need an overall guide of permutation / combination. I always get stumped on these kinds of problems, so is there an easy way to tackle these problems? Unfortunately, I don’t have an example to use, but if someone does please feel free to post. Whats the formula to use and/or shortcut etc. Please go in depth because this is one of my weaker points. It would save a lot of time if you could show an easy way to approach them. Thanks

EDIT - actually heres an example:

1 2 3 4 5

Imagine each number represents a card, and the card number ‘2’ can never be on either end, how many different assortments are there?