'Cause why not? n is the number of items in total r is the number of items in the group you are using to order Permutations calculates the number of possible orders you can put the desired objects into Combination is the number of ways you can group the objects into, order not being taken into account. comes with an improved calculator that solves factorials using the '!' for example, it can solve: 4!+3! 24+6 30
