Two friends have become quite competitive with their running.
Jolie runs for 15 minutes at an average speed of 6 miles per hour.
She then runs for 40 minutes at an average speed of 9 miles per hour.
It takes Alfie 45 minutes to run the same total distance that Jolie runs.
Work out Alfie’s average speed.
Give your answer in miles per hour.
Answer:
speed = distance/time, if we want our answer in mph distance must be in miles and time in hours.
We need to find the total distance Jolie ran in 2 parts since she changed speed.
6 = distance/0.25, multiply both sides by 0.25 to find that distance = 1.5miles
9 = distance/0.67, multiple both sides by 0.67 to find that distance = 6miles
Now we can find the speed of Alfie:
speed = 7.5/0.75 = 10mph