Problema Solution

two runners, one averaging 5 miles per hour and the other averaging 4 miles per hour, start at the same place and run along the same trail. the slower runner arrives at the end of the trail a half hour after the faster runner. how far did each person run?

Answer provided by our tutors

let


v1 = 5 mph the speed of the first runner


v2 = 4 mph the speed of the second runner


t1 = the time of the first runner


t2 = the time of the second runner


the slower runner arrives at the end of the trail a half hour after the faster runner:


t2 = t1 + 0.5


the distance = speed*time and since they run the same distance we have:


v1*t1 = v2*t2


5t1 = 4t2


plug t2 = t1 + 0.5 into the last equation:


5t1 = 4(t1 + 0.5)


by solving we find:


t1 = 2 hr


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v1*t1 = 5*2 = 10 mi


each person ran 10 miles.