A box of chocolates is randomly selected from a production line to check to see if any of the chocolates are faulty. Each box contains 12 chocolates with soft-centres and 8 with hard-centres. Two chocolates are randomly selected from the box and are tested to see if they have any faults.
a) P(two soft-centered chocolates) = (12/20) x (11/19) = 33/95 = 0.347.. = 0.35
b) P(soft-centred and hard-centred chocolate) = P(S and H, or H and S) = P(S, H) + P(H, S) = (12/20)x(8/19) + (8/20)x(12/19) = 48/95