Statistics & probability · SS2–SS3

Probability

How likely events are, including combined events, “and” and “or”, and tree diagrams.

Learn

  1. 1Probability and sample spacesProbability as favourable outcomes over possible outcomes: listing sample spaces, using tables of results, the complement, and 'or' with and without overlap.Done16 min
  2. 2Combined events and tree diagramsTwo or more events together: multiply for 'and', add for 'or', tree diagrams, draws with and without replacement, and 'at least one' by the complement.Done18 min

Practise

Answer probability questions one at a time. You'll know straight away whether you're right, with hints and the working step by step.

Your progress is saved on this device as you practise. No account needed.

Start practising

Past questions (129)

From 1983–2025: 64 WAEC, 12 NECO, 53 JAMB. Theory questions first, then objective, newest first.

Theory (50)

Objective (79)