A spy plane, whose average speed in still air is 250 mph, departs with a 40 mph tailwind

and returns to the same airport flying into the same wind. How far from the airport can
the plane fly if it has enough fuel to fly for 5 hours?

1 answer

time there= distance/290
time back=distance/210

5hours=distance(1/290 + 1/210)
5=distance(210+290)/(210*290)

distance=5*(60900)/(500)=609 miles