Combinations
Number of ways we can select n objects from a group of m distinct objects is m!/(n!*(m-n)!).
Example:
Number of possible ways to pick 4 oscar nominations from a list of 50 movies is 50!/(4!*(50-4)!)=50!/(4!*46!)=50*49*48*47/24=230300.
Remember:
This does not apply if there are identical objects.
