Latest Infosys Aptitude Question SOLUTION: Two men are going along a track rail in the opposite direction. One goods train crossed the first person in 20 sec. After 10 min the train crossed the other person who is coming i

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Two men are going along a track rail in the opposite direction. One goods train crossed the first person in 20 sec. After 10 min the train crossed the other person who is coming in opposite direction in 18 sec .After the train has passed, when the two persons will meet?

Solution

Let us consider that speed of train , first man and second man are respectively t, f and s.
According to first given condition goods train crossed the first person moving in same direction in 20 sec.
so length of the will be 20(t-f)
similarly train crossed the second man in 18 sec.
so length of the train will be 18(t+s)
on comparing these two equations, we get 20(t-f) = 18(t+s)
or 2t = 20f + 18s
or t = 10f + 9s
now it is given that After 10 min the train crossed the other person who is coming in opposite direction so
if we consider this way of train as L then the next equation will be
L = 600t (here 600 is used for 10 minutes)
finally as asked in the question the time required to meet the two man after the train has passed will be given by
time = (L-600 f)/(f+s) {here 600f is used for the distance traveled by first man in 10 minutes}
= (600t-600f)/(f+s)
= [600(10f+9s)-600f]/(f+s)
= 600(10f+9s-f)/(f+s) = 600*9(f+s)/(f+s) = 600*9 seconds = 600*9/60 min
= 90 minutes


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Asked In Infosys (14 years ago)

Solved Read Solution (4)

Is this Puzzle helpful?   (16)   (5) Submit Your Solution Time Distance and Speed

Read Solution (4) :

Ravi B Mali  (13 years ago)

72 minutes

Is this solution Helpfull? Yes (4) | No (4)  

mukesh ranjan mallick  (13 years ago)

This can be solved if we assume that both the persons are walking with the same
speed

Let the length of train be L,
the speed of the train be x m/s,
the speed of the men be y m/s
and the distance between the two men initially be D


The train took 20 seconds to cross a man going inthe same direction

So relative speed is x-y = L/20 m/s --- I

It took 18 seconds to cross the man coming in the opposite direction.

Again relative speed is x+y = L/18 ---- II

Solving both I and II
we get the speed of the train x = 19L/360 and
the speed of the man y= L/360

The train took 10 minuts to meet the man

Is this solution Helpfull? Yes (1) | No (6)  

C.T.Narayanan  (14 years ago)

190 Minutes

Is this solution Helpfull? Yes | No (1)  

vaibhav  (5 years ago)

Let ‘L’ be the length of train, ‘x’ be the speed of the first man,
‘y’ be the speed of the second man and
‘z’ be the speed of the train.

20=
1
(z−x)
and 18=
1
(z+y)

⇒ z=10x+9y

Distance between the two men =600(z+y) mt
Time =
600(z+y)−600(x+y)
(x+y)

=
600(9x+9y)
(x+y)

= 90 minutes

Is this solution Helpfull? Yes | No   

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