# RRB NTPC - Problems on Trains

1.

A 600 m long train crosses a pole in 9 sec, What is the speed of the train Km/hr ?

A.) 240
B.) 280
C.) 260
D.) 220

Speed of the train = Length / Time taken
=> 600 / 9 m /sec
= 200 / 3 m/sec
We need in kmph,
Speed = (20/3) x (18/5)
240 kmph

2.

A train travels from City X to City Y at a speed of 60 kmph, while on its return journey the train was travelling at speed of 120 kmph. Find the average speed of the train.

A.) 90
B.) 88
C.) 80
D.) 85

Given, Onward journey speed (x) = 60 kmph;
Return journeyspeed (y) = 120 kmph.
Average speed of the train = 2xy / (x + y)
Average speed = (2 x 60 x 120) / (60 + 120 )
= 14400 / 180
Average speed 80 kmph
Average speed of the train = 80 kmph.

3.

A 600m long train is running at 90 Kmph. how much time it will take to cross an electric pole?

A.) 16sec
B.) 20sec
C.) 24sec
D.) 22sec

Formula: D = S × T
600 = 90 Kmph × T
600 = 90 × 5/18 × T
Time = 24Sec

4.

The length of the bridge, which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds, is:

A.) 150 m
B.) 160 m
C.) 240 m
D.) 245 m

Speed = 45 x 5/18 m/sec = 25/2 m/sec.
Time = 30 sec.
Let the length of bridge be x metres.
Then, (130 + x)/30 = 25/2
2(130 + x) = 750
x = 245 m.

5.

The length of the bridge, which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds, is:

A.) 200 m
B.) 225 m
C.) 245 m
D.) 250 m