Question

When there is a 20.1 mihr wind, an airplane can fly 630 mi with the wind in the same time that it can fly 521 mi against the wind. Find the speed of the plane when there is no wind.

Answer 1

the speed of the plane when there is no wind is 212.25 mi/hr

Explanation:

Let v represent the speed of the plane without wind.

Wind speed = 20.1 mi/hr

The resultant speed with wind is;

v + 20.1 mi/hr

The resultant speed against wind is;

v - 20.1 mi/hr

Let t represent the time for the travel.

With wind;

(v+20.1)t = 630 ......1

Against wind;

(v-20.1)t = 521 ......2

Divide equation 1 by 2

(v+20.1)/(v-20.1) = 630/521

Cross multiply;

521(v+20.1) = 630(v-20.1)

Collecting like terms;

v(630-521) = 20.1(630+521)

v = 20.1(1151)/109

v = 212.25 mi/hr

the speed of the plane when there is no wind is 212.25 mi/hr