Nathan is buying shirts for his baseball team. He will pay $10.50 for each shirt plus a one time fee of $25.50 for the design. Which equation can be used to find y, the total cost to buy x shirts

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?