So it seems to me that you just have to figure our how many minutes it would take for Curtis to ride 6+3=9, so 9 miles. If it takes him one hour to ride 12 miles, how many minutes would it take for him to ride 9? so, 60/12 is equal to x/9, and solve. If you cross multiply and solve, you will get x=45, therefore it takes Curtis 45 minutes to ride 9 miles.
