What conditional probability means
What conditional probability means
Conditional probability asks for the chance of event BBB given that event AAA has already happened. It is written P(B∣A)P(B|A)P(B∣A). The words "given that" tell you that the sample space has been restricted to outcomes where AAA occurs.
Step-by-step lessons on Edexcel IGCSE Maths Conditional Probability. Each one builds up to exam-style questions. Build confidence with the shared Foundation-tier content first, since roughly 40% of Higher-tier marks are targeted at the grades 4–5 boundary that both tiers have in common.