SOLUTION: Sharon runs a single lap on a track in 100 seconds. Jessica runs the same lap in 90 seconds. If both start at the same time from the same point on the track and each maintains a co

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Question 281439: Sharon runs a single lap on a track in 100 seconds. Jessica runs the same lap in 90 seconds. If both start at the same time from the same point on the track and each maintains a constant rate, the number of minutes before Jessica laps Sharon is:
(A)9 (B) 11 (C) 13.5 (D) 15 (E) 18.5

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Sharon runs a single lap on a track in 100 seconds. Jessica runs the same lap in 90 seconds. If both start at the same time from the same point on the track and each maintains a constant rate, the number of minutes before Jessica laps Sharon is:
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On each lap Sharon gains 10 seconds on Jessi's time.
In 9 laps Sharon will have gained a full lap on Jessi.
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9 laps will take Sharon 900 seconds
900 seconds = 900/60 = 15 minutes
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Cheers,
Stan H.
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(A)9 (B) 11 (C) 13.5 (D) 15 (E) 18.5