the bar graph shows the number of hours you volunteered at an animal shelter what is the minimum numbers of hours you need to work in the 7th week to justify that you worked an average of 10 hours for the seven weeks explain your answer using measures of center​

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?