Problema Solution
A plane flies 495 miles with the wind and 440 miles against the wind in the same length of time. If the speed of the wind is 10 mph, find the speed of the plane in still air.
Answer provided by our tutors
v = d/t then t = d/v and since they did it in the same time:
440/(x -10) = 495/(x 10)440x 4400
= 495x -49509350
= 55×170
= x2. 1/15 1/8 1/x
= 1/48/120 15/120 1/x
= 30/12023/120 1/x
= 30/1201/x = 7/120x = 120/7x = 17.14