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

Question

Flying against the wind, a jet travels 3760 miles in 4 hours. Flying with the wind, the same jet travels 8520 miles in 6 hours. What is the rate of the jet in still air and what is the rate of the wind? Units are mi/h.

Answer 1

j - w = 3760/4 = 940 speed = distance divided by time

j +w = 8520/6 = 1420

add

2j = 2360

j = 1180 mph = jet speed in still air

subtract

2w = 480

w = 240 mph= wind speed