Free points just say aw

What is the inverse of the function f(x)=4x+8

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?

Jordan got 27 out of 90 correct on his test . what fraction of the marks did her get correct