Main content

Counting, permutations, and combinations

Learn
Count outcomes using tree diagramCounting outcomes: flower pots
Practice
The counting principleGet 3 of 4 questions to level up!
Learn
Permutation formulaZero factorial or 0!Factorial and counting seat arrangementsPossible three letter wordsWays to arrange colorsWays to pick officers
Practice
PermutationsGet 3 of 4 questions to level up!
Learn
Intro to combinationsCombination formulaHandshaking combinationsCombination example: 9 card hands
Practice
CombinationsGet 3 of 4 questions to level up!
Permutations & combinationsGet 5 of 7 questions to level up!
Learn
Probability using combinationsProbability & combinations (2 of 2)Example: Different ways to pick officersExample: Combinatorics and probabilityGetting exactly two heads (combinatorics)Exactly three heads in five flipsGeneralizing with binomial coefficients (bit advanced)Example: Lottery probabilityConditional probability and combinationsMega millions jackpot probabilityBirthday probability problem
Practice

About this unit

This unit covers methods for counting how many possible outcomes there are in various situations. We'll learn about factorial, permutations, and combinations. We'll also look at how to use these ideas to find probabilities.