SOLUTION: A train travels 300km at a constant speed of Vkm/h. If the train had travelled 5km/h faster, the journey would have taken two hours less. Find the speed of the train travelling at
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Question 937744: A train travels 300km at a constant speed of Vkm/h. If the train had travelled 5km/h faster, the journey would have taken two hours less. Find the speed of the train travelling at the lower speed. Found 2 solutions by stanbon, lwsshak3:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A train travels 300km at a constant speed of Vkm/h. If the train had travelled 5km/h faster, the journey would have taken two hours less. Find the speed of the train travelling at the lower speed.
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Original DATA:
dist = 300 km ; rate = V km/hr ; time = d/r = 300/V hours
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Faster DATA:
dist = 300 km ; rate = (V+5)km/hr ; time = 300/(V+5) hrs
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Equation:
time - time = 2 hrs
300/V - 300/(V+5) = 2 hrs
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300V + 1500 - 300V = 2V(V+5)
2V^2 + 10V - 1500 = 0
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V^2 + 5V - 750 = 0
Factor::
(V-25)(V+30) = 0
Positive solution::
Ans:: V = 25 km/hr
You can put this solution on YOUR website! A train travels 300km at a constant speed of Vkm/h. If the train had travelled 5km/h faster, the journey would have taken two hours less. Find the speed of the train travelling at the lower speed.
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let v=slower speed of trains
v+5=faster speed of train
travel time=distance/speed
..
lcd:v(v+5)
300v+1500-300v=2v(v+5)
1500=2v^2+10v
2v^2+10v-1500=0
v^2+5v-750=0
(v+30)(v-25)=0
v=25
lower speed of train=25 km/h
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