The distance between Mumbai and pune is 192km.travelling by the deccan queen,it takes 45min less then the other train.how do you find the speed of the deccan queen if the speeds of the two trains differ by 20kmph

Asked by aditya95 | 12th Aug, 2010, 06:19: PM

Expert Answer:

Td - Time by Deccan queen, and T be time by other train.
T - Td = 45 min = 3/4 hr
Vd - V = 20 km/hr 
VdT - VT = 20T 
VdT - 192 = 20T
(Vd - 20)T - 192 = 0
Now if we put for T = 3/4 + Td.
We'll still have two variables Vd and Td. So we can pick a value of Td and we get a value for Vd.
So many answers are possible.
For example, Td = 1/4, so that T = 1 hr.
Then Vd = 202 km/hr. and V = 192 km/hr
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Answered by  | 12th Aug, 2010, 10:59: PM

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