An airplane takes 5 hours to travel a distance of 3300 miles with the wind. The return trip takes 6 hours against the wind. Find the speed of the plane in still air and the speed of the wind.

The speed with the wind is (3300 mi) / (5 h) = 660 mi/h.

The speed against the wind is (3300 mi) / (6 h) = 550 mi/h.

The speed of the plane in still air is the average of these speeds, 605 mi/h.

The speed of the wind is the difference between the plane's speed in still air and its speed in moving air, 55 mph.