SOLUTION: nathan ran 2.5 miles at a pace of 7 minutes 36 seconds per . if he wishes to complete the entire 5 mile run at an average pace of 7 minutes 24 seconds per mile, what should his pac

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Question 1118647: nathan ran 2.5 miles at a pace of 7 minutes 36 seconds per . if he wishes to complete the entire 5 mile run at an average pace of 7 minutes 24 seconds per mile, what should his pace be for the next 2.5 miles?
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


For ease of calculations, change all the numbers to fractions.

2.5 miles = 5/2 miles
7 minutes 36 seconds = 7 3/5 minutes = 38/5 minutes
7 minutes 24 seconds = 7 2/5 minutes = 37/5 minutes

Then we want

(2.5 miles at 38/5 minutes per mile) + (2.5 miles at x minutes per mile) = (5 miles at 37/5 minutes per mile):

%285%2F2%29%2838%2F5%29%2B%285%2F2%29%28x%29+=+%285%29%2837%2F5%29
19%2B%285%2F2%29x+=+37
%285%2F2%29x+=+18
x+=+18%282%2F5%29+=+36%2F5

The rate he needs for the last 2.5 miles is 36/5 = 7 1/5 minutes per mile, or 7 minutes 12 seconds per mile.

Or.... If you understand problems like this, you can just say that for the first half of the race his pace was 12 seconds per mile over the average he wants, so the second half must be at a pace that is 12 seconds per mile under that average.