A plane can fly 800 miles in the same time as it takes a car to go 250 miles. If the car travels 110 mph slower than the plane, find the speed of the plane.

Answer 1

The speed P of the plane is given as 110 mph faster than that of the car C, so P = C + 110. Since they travel for the same amount of time T, P * T = 800 and C * T = 250 or T = 800/P = 250/C or 800C = 250P. Substituting gives us 800C = 250(C+110) -> 800C = 250C+27500 -> 550C = 27500 -> C=50. So the car is traveling at 50 mph and the plane at 50+110 or 160 mph.