Problema Solution
A university flew its football team round trip for a game with a rival university. The distance was 540 miles each way, and the round trip required a total flying time of 8.8 hours. Because of wind, the average speed of the plane in one direction was 30 miles per hour faster than it was in the opposite direction. What would be the speed of the plane in still air?
Answer provided by our tutors
First set up the problem:
Total distance flown was 540mi + 540mi = 1080mi
Total time = 8.8h
Now lets write an equation.
The toatl distance divided by the total time gives you the average speed.
So 1080mi / 8.8h = 122.73mi/h
Now 122.73mi/h is just the average speed. That means that when you add both speed up and divide by two you get 122.73
So lets write an equation for that.
122.73 = (X + (X + 30)) / 2
Multiply both sides by 2
245.46 = X + X + 30
Simplify
245.46 = 2X + 30
Subtract 30 from both sides
215.46 = 2X
Divide both sides by 2
107.73mi/h = X