Explain the difference for finding the probability for two evens that happen consecutively with an AND and finding the probability of two events with an OR. Help me it’s a math question

Fredrick designed an experiment in which he spun a spinner 20 times and recorded the results of each spin

Factor this polynomial completely x^2-64

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?