Question 3 Samantha ran 15 minutes more than John.
Anastasia ran twice as long as Samantha.
Anastasia ran for 60 minutes. The equation 2(x +
15) = 60 describes the situation.

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?