SOLUTION: Two runners leave the starting line at the same time.The first runner crosses the finish line in 15 minutes and averages 16 kilometers per hour. The second runner crossed the finis

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Question 661357: Two runners leave the starting line at the same time.The first runner crosses the finish line in 15 minutes and averages 16 kilometers per hour. The second runner crossed the finish line 5 minutes after the first runner. Find the second runner's speed.
I tried to divide 16 into 15 but don't understand it. The answer I got was not any of the choices. Thank you!
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Two runners leave the starting line at the same time.
The first runner crosses the finish line in 15 minutes and averages 16 kilometers per hour.
The second runner crossed the finish line 5 minutes after the first runner.
Find the second runner's speed.
:
First find the distance of the race from the 1st runners time and distance
He finished the race in 15 min which is 1/4 hr,
dist = speed * time
dist = 16 * 1/4
dist = 4 km:
:
With this information we can find the 2nd runners speed (s = dist/time)
The 2nd runner took 5 min longer than the 1st runner or 20 min which is 1/3 hr
:
s = 4/(1/3)
s = 4 * 3
s = 12 km/hr is the 2nd runners speed
:
Did this make sense to you now? C