During the Computer Daze special promotion, a customer purchasing a computer and printer is given a choice of five free software packages. There are 8 different software packages from which to select. How many different groups of software packages can be selected?

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?