Probability and complements
Probability and complements
Probability is a number from 000 to 111, where 000 means impossible and 111 means certain. For equally likely outcomes such as counters or cards, use the following formula:
Step-by-step lessons on Edexcel IGCSE Maths Probability Trees. 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.