Question

Ms. Cooper drove 18 miles in 31 hour. What is her speed in miles per hour?

Answer 1

1.72 
31 Divided by 18 =p

Answer 2

use the rule of 3 simple 

18 mls ---- 31 h
 x mls ----- 1 h
---------------------

x = 1*18/31 

x = 18/31 

her speed will be 18/31 miles per hour