Question

On a breezy day, Bonnie pedaled her human-powered aircraft 100 100 meters in 15 15 seconds going into the wind, and she made the return trip in 10 10 seconds with the wind. What were the speed of the wind and Bonnie's speed in still air? Use x x for the speed of the airplane in still air and y y for the speed of the wind

Answer 1

Against the wind 100 m 15 sec = 6.67 mtrs / sec
With the wind 100 m 10 sec = 10 mtrs / sec
psa means plane velocity in still air
ws means wind speed
psa -ws = 6.67
psa + ws = 10

Adding both equations we get:
2 * psa = 16.67
psa = 8.34 meters per second
Since psa + ws = 10 and psa = 8.34 then wind speed = 1.66 meters per second