Khan Academy: Permutations and Combinations: Permutations

Counting is not all it adds up to be — sometimes it involves multiplying. The lesson introduces permutations and combinations as ways of counting, depending upon whether order is important. Pupils learn about factorials and the formulas...

How many different ways can five people be arranged in any order in three chairs? Sal shows how combinations are different than permutations. He derives the formula for finding the combination without repetition.

A video that introduces the concept of combinations by building on knowledge of permutations. An arbitrary example is given and a formula for combinations is derived. This video also appears in the Probability strand. [10:11]

A video that introduces the concept of combinations by building on knowledge of permutations.

Video lesson finding the probability of making at least three out of five free throws by calculating combinations.

Video lesson introducing permutations by looking at examples and the formula. [10:11]

The last video in a three-part series on the Binomial Theorem from the Khan Academy. This segment illustrates how the Binomial Theorem is directly related to combinatorics using (a + b)^3 as an example. Students can clearly see how a...

Sal explains the permutation formula and how to use it.

Here's a sweet resource on sample spaces. An enticing interactive allows users to list all possibilities for the flavors of candy given to a friend. Scholars must also determine whether permutations or combinations are more...

Learning math from an ice cream shop—what a tasty treat! Individuals use an interactive to list all possibilities for a double-scoop ice cream. Along the way, they learn to distinguish between permutations and computations.