Problema Solution

A long distance runner starts at the beginning of a trail and runs at a rate of

4

miles per hour. Two hours later, a cyclist starts at the beginning of the trail and travels at a rate of

14

miles per hour. What is the amount of time that the cyclist travels before overtaking the runner?

Do not do any rounding.

Answer provided by our tutors

let


v1 = 4 mph the rate of the runner


t = the time of the runner before the cyclist passed him by


v2 = 14 mph the rate of the cyclist


t - 2 = the time of the cyclist and also t - 2 >0, t > 2


since the runner and the cyclist will pass the same distance and distance = speed*time we have:


v1t = v2(t - 2)


4t = 14(t - 2)


by solving we find:


t = 2.8 hr


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the cyclist travels t - 2 = 2 - 2.8 = 0.8 hours or 0.8*60 = 48 minutes.