Jeremy D. answered • 05/02/19
2 Masters Degrees, College Professor, Tutoring 5+ years
There are several ways to approach this problem. My personal preference is converting everything to MPH, which I believe keeps things simpler for me. So, I will do that here.
If the rider travels 0.75 miles (3/4 miles) in 5 minutes then this means (s)he travels 1.5 miles in 10 minutes or 9 miles in 60 minutes. This means the rider is traveling at 9 Miles per Hour (MPH).
The standard formula for distance is Rate x Time = Distance or more simply RT = D.
We are given the distance of 2.25 miles and we know our speed/rate. We are trying to solve for our time. We can write the equation with our known pieces of data as 9T = 2.25.
We divide both sides by 9 and we get T = 0.25 hours. A quarter of an hour is 15 mins. Therefore, it will take 15 mins to travel the 2.25 miles at the same rate of speed.
FYI - You may have noticed that the distance of 2.25 miles is exactly 3 times the distance of 3/4 mile. Which means it will simply take 3 times as long. 5 mins x 3 = 15 mins.
