Explain how you would use the commutative property of multiplication to answer 7x3

He that is measured at 220° is a reflex angle. the opposite angle is obtuse. find the measure of obtuse .

You deposit $5000 each year into an account earning 3% interest compounded annually. how much will you have in the account in 30 years?

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?