Flying against the wind, a jet travels 5180 mi in 7 hours. Flying with the wind, the same jet travels 6200 mi in 5 hours.

Question

What is the rate of the jet in still air and what is the rate of the wind?

Answer 1

R is the speed of the plane

S is the speed of the wind

 

( R+S)*5 = 6200

 

R+S = 1240

 

 

(R-S)*7 = 5180

 

R-S = 740

 

2R = 1980 <--- adds the bolded equations together

 

R = 1980/2 = 990

 

S = 250