Problema Solution
Carla and Vicki left the house at the same time and began traveling down the same road in the same direction. Carla drove at a speed of 60mph and Vicki at a speed of 65mph. how many hours was it before Vicki was 20 miles ahead of Carla?
Answer provided by our tutors
Let
v1 = 60 mph Carla's average speed
v2 = 65 mph Vicki's average speed
t = the time of the travel (in hours)
Since distance = speed*time we can find the distance that Carla and Vicky traveled in t hours:
In t hours Carla traveled: v1*t or 60t miles
In t hours Vicki traveled: v2*t or 65t miles
The difference in the distances is 20 miles:
65t - 60t = 20
5t = 20
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click here to see the equation solved for t
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t = 4 hr
It takes 4 hours before Vicki is 20 miles ahead of Carla.