Answer:
27mi/h
Explanation:
72 miles travelled in total.
1 travels 3 times as fast, so 7 divided into 4 equal parts, 1 part travlled by slower cyclist, and 3 parts by faster cyclist.
3/4 of 72 is 54 miles. If faster cyclist travelled 54 miles in 2 hrs, cyclist travelled 27 miles in 1 hour.