I got this question on my first Prep Test: A certain taxi driver charges a rate of r cents per person per mile. How much money, in dollars, would it cost three people to travel x miles if he gives them a 50% discount? (100 cents = 1 dollar) A) 3xr/2 B) 3x/200r C) 3r/200x D) 3xr/200 E) xr/600 Reviewi...