9514 1404 393
Answer:
21 miles per hour
Explanation:
Let w represent the wind speed. Then the travel time is ...
400/(329 +w) = 352/(329 -w)
400(329 -w) = 352(329 +w)
(352+400)w = 329(400 -352)
w = (400 -352)/(400 +352)·329 = 48/752·329 = 21
The wind speed is 21 miles per hour.