If y varies inversely as x, and y=12 when x=3, find y when x=4

Ben bowled 124 and 188 in his first two games. what must he bowl in his third game to have an average of at least 160?

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500

Factor the polynomial by its greatest common monomial factor.