A light aircraft travels 8 mph less than twice the speed of a motorcycle.If the motorcycle can travel 112 miles in the same time it takes the aircraft to travel 208 miles, then what is the average?

Answer 1

Let the speed of the bike be x

Then the speed of the plane will be 2x-8

The time will be y

Use the equation speed = distance/time or distance= speed*time

So the two equations will be:

Bike: 112=xy

plane: 208= (2x-8)y or 208= 2xy-8y

Since we know xy=112 we can put this into the plane equation:

208= 2(112)-8y Solve for y

8y=224-208

8y=16

y=2

Now put 2 instead of y in the bike equation

112=2x

x=66 mile per hour for the bike

the plane is 2(66)-8=106 miles per hour