24.4 Permutations

Permutations

Imagine, you want to withdraw cash from the ATM machine, but you forget the password of your account. The only thing you remember is that the password consists of the number 1, 2, 3, and 4. You are now trying to figure out the number of ways to arrange the numbers, and that’s permutations. Unlike combinations, order matters in permutations!

Lessons

Notes:
? permutation: nPr = number of arrangements of r items taken from a set of n distinct items (order matters!!)
= n!(nr)!\frac{{n!}}{{(n - r)!}}
Teacher pug

Permutations

Don't just watch, practice makes perfect.

We have over 3150 practice questions in Math 8 for you to master.