Problems on Trains - General Questions

 Problems on Trains - General Questions

1.	A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?

	120 metres
	180 metres
	324 metres
	150 metres

Answer: Option D

Explanation:

Speed=		60 x	5	m/sec	=		50	m/sec.
			18				3

Length of the train = (Speed x Time).

Length of the train =		50	x 9	m = 150 m.
		3

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2.	A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is:

	45 km/hr
	50 km/hr
	54 km/hr
	55 km/hr

Answer: Option B

Explanation:

Speed of the train relative to man =

125

m/sec

10

=

25

m/sec.

2

=		25	x	18	km/hr
		2		5

   = 45 km/hr.

Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr.

x - 5 = 45         x = 50 km/hr.

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

	200 m
	225 m
	245 m
	250 m

Answer: Option C

Explanation:

Speed =		45 x	5	m/sec	=		25	m/sec.
			18				2

Time = 30 sec.

Let the length of bridge be x metres.

Then,	130 + x	=	25
	30		2

2(130 + x) = 750

x = 245 m.

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4.	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 : 4
	None of these

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,

and length of the second train = 17y metres.

27x + 17y

= 23

x+ y

27x + 17y = 23x + 23y

4x = 6y

	x	=	3	.
	y		2

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5.	A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?

	120 m
	240 m
	300 m
	None of these

Answer: Option B

Explanation:

Speed =		54 x	5	m/sec = 15 m/sec.
			18

Length of the train = (15 x 20)m = 300 m.

Let the length of the platform be x metres.

Then,

x + 300

= 15

36

x + 300 = 540

x = 240 m.