Sue has 18 sweets. Tony also has 18 sweets. Sue gives Tony x sweets. Sue then eats 5 of her sweets. Tony then eats half of his sweets. Write the expression for the number of sweets Sue and Tony now have.

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?