Pls help me with this! (10 points) pls show work if u can do I can understand! Thank you!

At school there are 526 students and 263 are girls about how likely is it that a randomly chosen student will be a boy

What is the value of x? enter your answer in the box. (cm)

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?