36. Two ta
5. A train covers a distance of 90 km at a uniform speed.
If the speed of the train is increased by 15 km/hr., it
takes 30 minutes less in the journey. Find the original
speed of train
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Answer:
Step-by-step explanation:
Answer:
Step-by-step explanation:
original speed be x km/hr
distance =90km
time taken=90/x
new speed=x+15
distance=90
now time taken=90/x+15
time difference=30 min=1/2 hr
as per ques.
90/x - 90/x+15 = 1/2
solve it
90x+1350-90x=0.5x(x+15)
1350=0.5x^2+7.5x
x^2+15x-2700=0
x=45,-60
so speed=45km/hr
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