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.
Practise Edexcel A Level Maths Conditional Probability with exam-style questions for A Level Maths. 100 questions covering Set Notation, Conditional Probability, Conditional Probabilities in Venn Diagrams, Probability Formulae, and Tree Diagrams, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.