Question

Flying against the wind, a jet travels 4060 miles in 7 hours. Flying with the wind the same jet travels 3760 miles in 4 hours. What is the rate of the jet in still air and what is the rate of the wind?

Answer 1

Explanation:

let j = jet speed in still air

let w be wind speed

(j - w)7 = 4060

7j - 7w = 4060

7j = 7w + 4060

j = w + 580

(j + w)4 = 3760

4(w + 580) + 4w = 3760

4w + 2320 + 4w = 3760

8w = 1440

w = 180 mi/hr

j = 180 + 580 = 760 mi/hr

Supersonic at most altitudes. No aircraft ever built could maintain supersonic speeds for more than about 4 hours due to fuel requirements, so a 7 hour flight time is just for theoretical math questions.