A light house blinks every 12 minutes. A second light house lighthouse blinks every 10 minutes if they both blink at 8:10 P. M., at what time will they next blink together?

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?