You are a person that can run 8.5 miles per hour. Your friend wants to race you in a 20 mile race and he can run 8.0 miles per hour. You take a stop for 5 minutes every mile. Your friend takes a stop for 2 minutes every 1.5 miles.
Will you win or lose and by how much?
October 21st, 2011 | Category: 
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The whole trip would take me:
20/8.5 + (20/1)x5/60 = 4 hours 1 min and 10 seconds
My friend would do it in
20/8 + (20/1.5)x2/60 = 2 hours 56 min and 40 seconds
He wins by 1 hour 4 min and 30 seconds …
As Roolstar has indicated, the friend would win. However, while calculating the time spent on taking the break, we have to consider 19 stops instead of 20 while calculating ‘my’ time (20th stop would be the finishing line :)). In case of our friend, it is (19.5/1.5 = 13). So, the time is:
My case: (20/8.5) + (19×5/60) = 3h 56.17m
Friend’s case: (20/8) + (19.5/1.5 x 2/60) = 2h 56m
Close enough Kim, You would lose the race by an hour.
If you ran continuously, you would finish in 20 / 8.5 * 60 = 141 min. With the nineteen breaks, your final time would be 141 + 19 * 5 = 236 min.
Without breaks, your friend would finish in 20 / 8.0 * 60 = 150 min. With the thirteen breaks, their final time would be 150 + 13 * 2 = 176 min.
Therefore, your friend would win by a whopping 60 min, or a whole hour.
You are today’s winner.