A website Maths Puzzle Numerical Ability Time Distance and Speed

Two trains, each 400 meters long, pass each other completely in 10 seconds when they are moving in opposite directions. Moving in the same direction, they pass each other completely in 20 seconds. Find the speed of the faster train.

Read Solution (Total 1)

Let s1 be the faster train's speed nd s2 be the slower train speed
Moving in opposite direction
(d1+d2)/(s1+s2) = t1
800/(s1+s2) = 10
s1+s2 = 80 --> (1)

Moving in same direction
(d2+d2)/(s1-s2) = t2
800/(s1-s2) = 20
s1 - s2 = 40 --> (2)
solving (1) nd (2)
2s1 = 120 ==> s1 = 60m
s2 = 20 m

Speed of faster train is 60 m/s

Abs : 60 m/s
10 years agoHelpfull: Yes(17) No(0)

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