Question

At maximum speed, an airplane travels 2460 miles against the wind in 6 hours. flying with the wind, the plane can travel the same distance in 5 hours. what is the speed of the plane with no wind?

Answer 1

Explanation:

R is the speed of the plane

S is the speed of the wind

(R-S)*7 = 7490 <--- against the wind

(R+s)*9 = 11610 <--- with the wind

Distributes:

7R - 7S = 7490

9R + 9S = 11610

Multiplies the top equation by 9

and the bottom equation by 7

63R - 63S = 67410

63R + 63s = 81270

126R = 148680

R=1180

Plugs into original first equation

(R-S)*7 = 7490

(1180-s)*7 = 7490

1180 - s = 7490/7

1180 - s = 1070

-s = -110

s = 110

The speed of the plane in still air is 1180

The spped of the wind is 110

This is awfully fast.