In a factory, machines AAA, B B\,B and C C\,C are all producing metal rods of the same length. Machine A A\,A produces 35% of the rods, machine B B\,B produces 25% and the rest are produced by machine CCC. Of their production of rods, machines AAA, B B\,B and C C\,C produce 3%, 6% and 5% defective rods respectively.
Draw a tree diagram to represent this information.
Find the probability that a randomly selected rod is
(i) produced by machine A A\,A and is defective,
(ii) is defective.
Given that a randomly selected rod is defective, find the probability that it was produced by machine CCC.
11 exam-style questions on Edexcel A Level Old Maths Probability. Each one has a worked solution and a mark scheme showing where the marks go.