A Delta 727 traveled 2520 miles

Question

A Delta 727 traveled 2520 miles with the wind in 4.5 hours and 2160 miles against the wind in the same amount of time. Find the speed of the plane in still air and the speed of the wind.

Answer 1

Let x = speed of plane in still air

     y = speed of wind

 

Distance = (rate)(time)

 

Speed against wind = x - y, so       4.5(x - y) = 2160

Speed with the wind  = x + y, so,  4.5(x + y) = 2520

 

Divide both equations by 4.5 to get:  x - y = 480

                                                        x + y = 560

 

Adding the equations we have 2x = 1040

                                                x = 520  and y = 560 - x = 40

 

The speed of the plane in still air is 520 mph and the speed of the wind is 40 mph.