When you put money in the bank and draw interest, the amount put in your account later on is given by the expression: p + prt, where p is the principle, r is the rate of interest, and t is the time. factor the expression.

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?