Jet travels in air

Question

A jet travels 3405 miles against the wind in five hours and 4305 miles with the wind in the same amount of time what is the right of the jet in still air and what is the rate of the wind

Answer 1

j - w = 3405/6 = 681

j+w = 4306/4 = 861

add

2j = 681+861 = 1542

j = 1542/2 = 771 mph in still air

w = 861-771 = 90 mph = wind speed