If the order doesn’t matter then we have a combination, if the order does matter then we have a permutation. One could say that a permutation is an ordered combination. The number of permutations of n objects taken r at a time is determined by the following formula: P(n,r)=n!
How do you solve permutations examples?
For example, let’s say you have 16 people to pick from for a 3-person committee. The number of possible permutations is: 16! / (16 – 3)! = 16! / 13!
n! / (n – r)!
N is the number of things you are choosing from,r is the number of items.“!” is a factorial of a number. (See: What is a factorial of a number?)
How do permutations work?
A simple approach to visualize a permutation is the number of ways a sequence of a three-digit keypad can be arranged. Using the digits 0 through 9, and using a specific digit only once on the keypad, the number of permutations is P(10,3) = 10! / (10-3)! = 10! / 7! = 10 x 9 x 8 = 720.
