rate of wind problem

Question

Flying a plane with the wind took 6 hours to go 720 miles. On the

return trip against the wind the plane took 9 hours. How long would

it take the plane flying at the same speed with no wind?

Answer 1

p+w x 6 = 720

p+w = 120

p-w x 9 = 720

p-w = 80

2p = 120+80 = 200

p = 100 mph plane speed with no wind

w = 120-100 = 20 mph = wind speed