A-level · Probability

Conditional probability and tree diagramsExam-style questions

Using tree diagrams where the second-stage branches are conditional probabilities — multiplying along branches for P(A ∩ B), adding the paths to an event, and reversing the condition to find P(first | second).

Start practising Read the lesson

19 questions · A-level level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 2Level 3Level 4Level 5
  1. 1
    A bag contains 33 red and 22 blue counters. Two are drawn at random without replacement. Find the probability that both are red.
    Level 2 · 2 marksTry it