What value of c makes x^2-12x+c a perfect square trinomial

Which graph represents the solution of the inequality?

Find the solutions for a triangle with a =16, c =12, and b = 63º

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?