SOLUTION: A lorry and a car travel uniformly along expressway from city A to city B . Thw lorry leaves at 915 amd arrives at 1315. The car leaves at 1000 and arrive at 1245. At what time did

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Question 626682: A lorry and a car travel uniformly along expressway from city A to city B . Thw lorry leaves at 915 amd arrives at 1315. The car leaves at 1000 and arrive at 1245. At what time did the car overtake the lorry.?
Answer by fcabanski(1391) About Me  (Show Source):
You can put this solution on YOUR website!
d = r * t (Distance is rate times time).


Call the lorry's speed L and the car's speed C.


The distance they travel is the same, so 4L = 2.75C


The distance the car must make up in some time (t) is the time of head start the lorry had, times the lorry's speed, which is: .75L and that equals the car's speed times the time (t) so .75L = Ct


Use the first equation to find L in terms of C. 4L=2.75C so L = 2.75/4 * C = .6875C.


Substitute that into the second equation:
.75(.6875C) = Ct so .515625C = Ct and .515625 = t = approx 30.9 minutes.


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