Find the speed of the marathoner.

Question

An ultra-marathoner passes the 15-mi point of a race after 2 hr and reaches the 22-mi point 56 min later. Assuming a constant rate, find the speed of the marathoner. 

Answer 1

distance=rate*time

15=r*2

r=15/2

r=7.5 mph

or,...

22=r*(2 56/60)

22=r*(2 14/15)

22=r*(44/15)

22(15/44)=r(44/15)(15/44)

15/2=r

7.5=r again