Two bags, A A\,A and BBB, contain red, green and yellow counters. Bag A A\,A contains 3 red, 2 green and 4 yellow. Bag B B\,B contains 5 red, 4 green and 1 yellow. Taylor picks one counter at random from bag A A\,A and places it into bag BBB. She then picks one counter at random from bag BBB.
Draw a tree diagram to represent this information.
Find the probability that Taylor picks two counters of the same colour.
Given that both counters are the same colour, find the probability they are both yellow.
330 exam-style questions on Edexcel A Level Maths Conditional Probability, covering 2.1 Set Notation, 2.2 Conditional Probability, 2.3 Conditional Probabilities in Venn Diagrams, 2.4 Probability Formulae, and 2.5 Tree Diagrams. Each one has a worked solution and a mark scheme showing where the marks go.