Problema Solution
An express train and a car leave a town the same time and head for another town 280 miles away. The rate of the train is twice the rate of the car. The the train arrives 4 hours before the car arrives. Find the rate of the car.
Answer provided by our tutors
Let
v = the rate of the car
2v = the rate of the train
t = the time of the car
t - 4 = the time of the train
d = 280 mi the distance
d = v*t
d = 2v*(t - 4)
Now we can write:
vt = 2v(t - 4) divide both sides by v
t = 2(t - 4)
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click here to see the equation solved for t
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t = 8 hr
v = d/t
v = 280/8
v = 35 mph
The rate of the car is 35 mph.