Time, Speed & Distance

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A train starts from Delhi at 6:00 am and reaches Ambala cantt. at 10am. The other train starts from Ambala cantt. at 8am and reached Delhi at 11:30 am, If the distance between Delhi and Ambala cantt is 200 km, then at what time did the two trains meet each other?


8:46 am


8:30 am


8:56 am


8:50 am

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Option(C) is correct

Average speed of train leaving Delhi = \(\dfrac{200}{4}=50\) km/hr

Average speed of train leaving Ambala cantt. = \(200\times \dfrac{2}{7}=\dfrac{400}{7}\)

By the time the other train starts from Ambala cantt, the first train had travelled 100 km

Therefore, the trains meet after:


\(=\dfrac{14}{15}\times 60=56\)minutes

Hence they meet at 8:56 am

(5) Comment(s)


Why do we multiply second train by 2/7?


400/3.5=400*2/7.......,where 3.5 is the time difference between 8am and & 11.30 am

Nairuti Suradkar

Let t be the start time

A starts at t, while B starts at (t-2)

total distance covered is 200 km

as they are travelling in opposite direction,

relative dist covered

i,e 200=((200/4)*t )+((400/7)*(t-2))


i.e 2hrs 56min from start (6 am)

therefore they meet at 8.56am.





$\dfrac{14}{15} \times 60 =56$


Thanks Pree for the input, corrected now.