12
Q:

Two trains of equal length , running in opposite directions , pass a pole in 18 and 12 seconds. The trains will cross each other in 

A) 14.4 sec B) 15.5 sec
C) 18.8 sec D) 20.2 sec

Answer:   A) 14.4 sec

Explanation:

Let the length of the train be L metres

Speed of first train = \inline \frac{3600}{18}\times L m/hour

Speed of secxond train = \inline \frac{3600}{12}\times L m/hour

When running in opposite directions, relative speed = 200 L + 300 L m/hour

Distance to be covered = L + L = 2L metre

Time taken = \inline \frac{2L}{500L}\times 3600 sec

                 =14.4 sec

Q:

Two trains namely X & Y leave station 'A' at 6.30am and 7.40am and travel at 30km/hr and 40 km/hr respectively. How many kms from 'A' will the trains meet ?

A) 140 kms B) 120 kms
C) 96 kms D) 142 kms
 
Answer & Explanation Answer: A) 140 kms

Explanation:

It is given train X leave station A at 6:30 am, here it is asked to calculate the distance from A when the trains meet, the
Distance traveled by train left at 6:30 am upto 7:40 am i.e. in 1 hr. 10 min. or 7/6 hours = 30 x 7/6 = 35 km
So train leaving at 7:40 am will meet first train after covering a distance of 35 km. with relative speed of 40-30=10 km/hr.
Hence time taken = 35/10 = 3.5 hours or 3 hours 30 minutes
So distance from A = Distance traveled by 2nd train in 3 hr. 30 min
= 40 x 3.5 = 140 km.

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1 6
Q:

Two goods trains each 520 m long, are running in opposite directions on parallel tracks. Their speeds are 42 km/hr and 36 km/hr respectively. Find the time taken by the slower train to cross the driver of the faster one ?

A) 60 sec B) 48 sec
C) 45 sec D) 34 sec
 
Answer & Explanation Answer: B) 48 sec

Explanation:

Relative speed = 42 + 36 = 78 km/hr =  m/s
Distance = (520 + 520) =1040 mts.
Time = = 48 sec

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5 253
Q:

Two trains are running at 60 km/hr and 20 km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 6 seconds. What is the length of the fast train ?

      

A) Option A B) Option B
C) Option C D) Option D
 
Answer & Explanation Answer: A) Option A

Explanation:

As Trains are moving in same direction,
Relative Speed = 60-20 = 40 kmph
  m/sec

Length of Train= Speed * Time

Length = 

 

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6 205
Q:

Length of train is 170 meters and speed of train is 63 km/hour. This train can pass a bridge in 30 seconds, then find the length of the bridge.

A) 355 mts B) 325 mts
C) 365 mts D) 312 mts
 
Answer & Explanation Answer: A) 355 mts

Explanation:

Given speed = 63 km/hr =  m/s
Let the length of the bridge = x mts
Given time taken to cover the distance of (170 + x)mts is 30 sec.
We know speed =  m/s

 

 x = 355 mts.

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5 177
Q:

A train running at the speed of 40 km/hr crosses a signal pole in 9 seconds. Find the length of the train ?

A) 90 mts B) 150 mts
C) 120 mts D) 100 mts
 
Answer & Explanation Answer: D) 100 mts

Explanation:

We know that  

 distance= speed * time
 d = 

  d= 100 mts.

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5 214