Problema Solution

The average speed of one airplane is 200 mph faster than that of an automobile. If the automobile starts at 3 a.m. and the airplane starts from the same place at 11 a.m., they will have traveled the same number of miles by 1:00 p.m.

If r represents the rate of the automobile, how many miles does the plane travel?

Answer provided by our tutors

time for airplane = 11 am to 1 pm = 2 hr

distance travelled by plane = 2a ------- (speed of plane is a mph)


time for auto = 3 am to 1 pm = 10 hr

distance travelled by plane = 10(a - 200) 


2a = 10(a - 200)

8a = 2000

a = 250 mph ----- plane

and 250 - 200 = 50 mph ----- auto