An electric motor pumps water into a pool at a rate of 500 liters per hour. After a tune
up, its rate increases by x liters per hour. If the motor now takes 3 hours 19 pump
1800 liters, in which equation does x represent the increase in speed after the tune
up?
A, 500(2+3) 1800
B, 3(500) +2 1800
C. 5002 +3 1800
D, 3(500 + 2) 1800