A certain NYC taxi driver has decided to start charging a rate of r cents per person per mile. How much, in dollars, would it cost 3 people to travel x miles if he decides to give them a 50% discount? Choose the correct choice from the following:	A) 3xr/2	B) 3x/200r	C) 3r/200x	D) 3xr/200	E) xr/600
r/100 dollars per person per mile   one person going x miles will be charged rx/100   50% discount = rx/200   3 such people = 3rx/200 ;   ANSWER:3xr/200
<result>D</result>
A certain NYC taxi driver has decided to start charging a rate of r cents per person per mile. How much, in dollars, would it cost 3 people to travel x miles if he decides to give them a 50% discount?