A jar contains 7 yellow marbles, 5 purple marbles, and 8 green marbles. Two marbles are selected at random from the jar without replacement.
Draw a tree diagram to represent this information.
Find the probability that both marbles selected are purple.
Given that at least one of the marbles selected is yellow, find the probability that both marbles are yellow.
164 exam-style questions on WJEC A Level Maths 4.1 Probability (A-level only), covering 4.1.1 Probability (A-level only), 4.1.2 Probability (A-level only), and 4.1.3 Probability (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.