# Math

posted by
**Rebecca** on
.

An airplane flies 500 mi/h in still air. Flying with the jet stream, the plane travels 1200 mi from City A to City B. The plane then returns to City A, flying against the jet stream. The round-trip flight time is 5 h. What is the speed of the jet stream in miles per hour?

A: 25 mi/h

B: 100 mi/h

C: 150 mi/h

D: 223 mi/h