a A sum of 5 6 or 7 and the probability of getting b Doubles or a sum of 6 or 8 c A sum greater than 8 or less than 3 d Based on the answers to part a b and c which is least likely to occur Explain why 9 An urn contains 6 red marbles 2 green marbles 1 blue marbles and 1 white marble If a marble is drawn find the probability of getting a red or a white marble