9514 1404 393
Answer:
216 mi/h
Explanation:
The time for the trip with the wind is ...
(1080 mi)/(225 +45 mi/h) = 4 h
The time for the trip against the wind is ...
(1080 mi)/(225 -45 mi/h) = 6 h
The average speed for the entire round trip is ...
(2160 mi)/(4 +6 h) = 216 mi/h