Intermediate Algebra

Question

A sales executive traveled 75 mi by car and then an additional 1400 mi by plane. The rate of the plane was eight times faster than the rate of the car. The total time for the trip was 5 h. Find the rate of the plane.

Answer 1

Let x = rate of speed car

-75 mi at x mph

-1400 mi at 8x mph

-Total time 5 hr

75/x + 1400/8x =5

600/8x + 1400/8x = 5

2000/8x = 5

2000 = 40x

x = 50

Plane = 8x = 8(50) = 2400

The plane was traveling 2400 mph.