Answer:
- jet: 975 km/h
- wind: 75 km/h
Explanation:
Given that a jet makes a round trip of 13600 km taking 6:48 hours with the wind and 8 hours against the wind, you want to know the speed of the jet in still air, and the speed of the wind.
Setup
Each leg of the trip is 13600/2 = 6800 km. The speed in each direction is ...
speed = distance/time
If j represents the jet speed and w represents the wind speed, we have ...
j + w = (6800 km)/(6.8 h)
j - w = (6800 km)/(8 h)
Solution
Adding the two equations gives ...
(j +w) +(j -w) = (1000 km/h) +(850 km/h)
2j = 1850 km/h
j = 925 km/h
Then the wind speed is ...
925 km/h + w = 1000 km/h
w = 75 km/h . . . . . . . subtract 925 km/h
The rate of the jet is 925 km/h; the rate of the wind is 75 km/h.