Conditional Probability

Work out the probability of an event when you already know something else has happened — including without-replacement problems.

Conditional Probability from Venn Diagrams & Two-Way Tables

Extract conditional probabilities directly from a Venn diagram or two-way table by restricting your view to the given condition's row or region.

What Is Conditional Probability?

Understand what it means for one event to be conditional on another, and learn the P(A|B) notation with a clear worked example.

Probability Without Replacement

Find probabilities when items are picked and not put back, adjusting the numerator and denominator for each pick in a tree diagram.