Problema Solution

Justin drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 6 hours. When Justin drove home, there was no traffic and the trip took 4 hours. If his average rate was 22 miles per hour faster on the trip home, how far away does Justin live from the mountians?

Answer provided by our tutors

let


v1 = the average rate on the way to the mountains


t1 = 6 hr the time of the trip to the mountains


v2 = the average rate on the way back from the mountains


t2 = 4 hr the time of the trip back from the mountains


d = the distance to the mountains


his average rate was 22 miles per hour faster on the trip home:


v2 = v1 + 22


since distance = speed*time we have:


d = v1*t1 = v2*t2


6v1 = 4v2


by solving the system of equations:


v2 = v1 + 22


6v1 = 4v2


we find:


v1 = 44 mph


v2 = 66 mph


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d = v1*t1


d = 6*44


d = 264 mi


Justin lives 264 miles away from the mountains.