Question 676983: Two runners start a race at the same time, traveling in the same direction. Runner 1 runs at a rate of 5 mph, runner two at a rate of 7.5 mph. How long will it be when the runners are 8.75 miles apart?
Answer by jpvn2015(54)   (Show Source):
You can put this solution on YOUR website! The first thing to note is that Runner Two is going 2.5 mph faster than Runner 1. Thus, after three hours, Runner Two is going to be 7.5 miles further up the road from Runner 1.
Since R2 is 7.5 greater than R1 after 3 miles, he will be 10 greater after 4 miles. The average between 7.5 and 10 is 8.75...thus your answer would be the average of 3 and 4.
So, 3 hours and 30 minutes falls right between 3 and 4 hours, thus your answer yields: 3 hours and 30 minutes
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