The Multiplication Rule of Probability

The Multiplication Rule of Probability ("AND")

This video covers the multiplication rule for probability which is used in "and" problems, such as the probability of rolling two dice and getting a 5 "and" a 6, or flipping two coins and getting a head "and" a tails. (As the name implies, multiplication is involved.)

5% Fudge Rule for Multiplication Rule

This is a quick video explaining when you're allowed to sort of pretend that dependent events -- such as drawings "without replacement" -- are "close enough" to independent that you can do the math as if they're independent. Hint: the cutoff is around 5 percent.

Hybrid Multiplication & Addition Rule Problems

Often in probability word problems, you're going to need a combination of these two rules because outcome probabilities that you calculate with the multiplication rule have to be added up to get the overall probability of a compound event. Things like rolling even numbers in dice, or flipping some combination of heads and tails.