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In what time will a train 100 meters long cross an electric pole, if its speed is 144 km/hr

  • 5 seconds
  • 4.5 seconds
  • 3 seconds
  • 2.5 seconds

Answer: Option D

Explanation:

First convert speed into m/sec

Speed = 144*(5/18) = 40 m/sec

Time = Distance/speed
= 100/40 = 2.5 seconds

Similar Questions :

1. Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is ?

  • 1:3
  • 3:2
  • 3:5
  • 3:7

Answer: Option B

Explanation:

Let the speeds of the two trains be x m/sec and y m/sec respectively.

Then, length of the first train = 27x metres,
Length of the second train = 17y metres.
[because distance = speed*time]

27x+17yx+y=23=>27x+17y=23x+23y=>4x=6y=>xy=64


So ratio of the speeds of train is 3:2

2. Two trains 140 metre and 160 metre long run at the speed of 60 km/hr and 40 km/hr respectively in opposite direction on parallel tracks. What time these will take to cross each other ?

  • 10.7 Seconds
  • 10.8 Seconds
  • 10.9 Seconds
  • 11.8 Seconds

Answer: Option B

Explanation:

Relative Speed = 60+40 = 100 Kmph
= 100*(5/18) = 250/9 m/sec

Distance to be covered = 140 + 160 = 300 metres

Time = Distance/Speed

Time=300∗9250=545=10.8 seconds

3. A train is running with a speed of 60 kmph and its length is 110 metres. Calculate the time by which it will pass a man running opposite with speed of 6 kmph.

  • 2 second
  • 4 second
  • 6 second
  • 8 second

Answer: Option C

Explanation:

From the given question,
we will first calculate the speed of train relative to man,
=> ( 60 + 6 ) = 66 km/hr ( we added 6 because man is running opposite )
Convert it in metre/second
=66×518=553m/secTime it will take to pass man =110×355=6 seconds



4. Two trains are running in opposite directions in the same speed. The length of each train is 120 meter. If they cross each other in 12 seconds, the speed of each train (in km/hr) is

  • 30 Km/hr
  • 36 Km/hr
  • 80 Km/hr
  • 90 Km/hr

Answer: Option B

Explanation:

Distance covered = 120+120 = 240 m
Time = 12 s

Let the speed of each train = x.
Then relative velocity = x+x = 2x

2x = distance/time = 240/12 = 20 m/s

Speed of each train = x = 20/2 = 10 m/s

= 10*18/5 km/hr = 36 km/hr

5. Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time which they take to cross each other, is

  • 9.8 seconds
  • 10.8 seconds
  • 11.8 seconds
  • 12.8 seconds

Answer: Option B

Explanation:

Relative Speed = 60+40 = 100 kmph
= 100*(5/18) = 250/9 m/sec

Distance = 140+160 = 300 meters

Time = Distance/Speed

300∗9250=545=10.8 seconds



So the time trains will take to cross each other will be 10.8 seconds

Read more from - Problems on Trains Questions Answers
Post a comment

  • KuMaR TN 9 years ago

    Tq so much sir

    mastguru 9 years ago replied

    welcome PSM !

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