Chen has three boxes. Box A holds 5 counters, consisting of 3 white counters and 2 yellow counters. Box W contains 4 red marbles and 3 blue marbles, and Box Y contains 5 red marbles and 3 blue marbles. Chen picks one counter at random from box A. If the counter is white, he then selects two marbles from box W, at random and without replacement. If the counter is yellow, he then selects two marbles from box Y, at random and without replacement.
(a)[3]
Produce a fully labelled tree diagram to represent this information, and include all the probabilities.
(b)[3]
Find the probability that one red marble and one blue marble are obtained.
(c)[2]
Find the probability that a white counter is chosen from box A, given that one red marble and one blue marble are obtained.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The 3-tier tree layout is correct.” …