Speed, Time and Distance
 A train, 150 m long, takes 30 seconds to cross a bridge 500 m long. How much time will the train take to cross a platform 370 m long ?

 36 secs
 30 secs
 24 secs
 18 secs

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When a train croses a bridge, distance covered = length of (bridge + train).
∴ Speed of train = 150 + 500 30 = 650 = 65 m/sec. 30 3
∴ Time taken to cross the 370m long platform= 370 + 150 65 3 = 520 × 3 = 24 seconds 65 Correct Option: C
When a train croses a bridge, distance covered = length of (bridge + train).
∴ Speed of train = 150 + 500 30 = 650 = 65 m/sec. 30 3
∴ Time taken to cross the 370m long platform= 370 + 150 65 3 = 520 × 3 = 24 seconds 65
 A train takes 18 seconds to pass through a platform 162 m long and 15 seconds to pass through another platform 120 m long. The length of the train (in m) is :

 70
 80
 90
 105

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Let the length of the train be x metres.
When a train corsses a platform it covers a distance equal to the sum of lengths of train and platform. Also, the speed of train is same.∴ x + 162 = x + 120 18 15
⇒ 6x + 720 = 5x + 810
⇒ 6x – 5x = 810 – 720
⇒ x = 90
∴ The length of the train = 90m.Correct Option: C
Let the length of the train be x metres.
When a train corsses a platform it covers a distance equal to the sum of lengths of train and platform. Also, the speed of train is same.∴ x + 162 = x + 120 18 15
⇒ 6x + 720 = 5x + 810
⇒ 6x – 5x = 810 – 720
⇒ x = 90
∴ The length of the train = 90m.
 A train is moving at a speed of 132 km/hour. If the length of the train is 110 metres, how long will it take to cross a railway platform 165 metres long?

 5 seconds
 7.5 seconds
 10 seconds
 15 seconds

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When a train crosses a railway platform, it travels a distance equal to sum of length of platform and its own length.
Speed = 132 kmph= 132 × 5 = 110 m/sec 18 3
∴ Required time= 110 + 165 seconds 110 3 = 275 × 3 = 7.5 seconds 110
Second Method :
Here, x = 110m,
u = 132 km/hr.= 132 × 5 = 110 m/sec 18 3
y = 165m, t = ?
usingt = x + y u t = 110 + 165 110 3 t = 275 × 3 110 = 25 × 3 = 15 = 7.5 sec 10 2 Correct Option: B
When a train crosses a railway platform, it travels a distance equal to sum of length of platform and its own length.
Speed = 132 kmph= 132 × 5 = 110 m/sec 18 3
∴ Required time= 110 + 165 seconds 110 3 = 275 × 3 = 7.5 seconds 110
Second Method :
Here, x = 110m,
u = 132 km/hr.= 132 × 5 = 110 m/sec 18 3
y = 165m, t = ?
usingt = x + y u t = 110 + 165 110 3 t = 275 × 3 110 = 25 × 3 = 15 = 7.5 sec 10 2
 A train 800 metres long is running at the speed of 78 km/hr. If it crosses a tunnel in 1 minute, then the length of the tunnel (in metres) is :

 77200
 500
 1300
 13

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When a train crosses a tunnel, it covers a distance equal to the sum of its own length and
tunnel.
Let the length of tunnel be x
Speed = 78 kmph= 78 × 1000 m/sec. = 65 m/sec. 60 × 60 3 ∴ Speed = Distance Time ⇒ 65 = 800 + x 3 60
⇒ (800 + x ) × 3 = 65× 60
⇒ 800 + x = 65 × 20 m
⇒ x = 1300 – 800 = 500
∴ Length of tunnel = 500 metres.
Second Method :
Here, x = 800 m,
u = 78 km/hr= 78 5 = 65 m/sec 18 3
t = 1 min = 60 sec, y = ?
usingt = x + y u 60 = 800 + y 65 3 60 × 65 = 800 + y 3
1300 – 800 = y
y = 500 metresCorrect Option: B
When a train crosses a tunnel, it covers a distance equal to the sum of its own length and
tunnel.
Let the length of tunnel be x
Speed = 78 kmph= 78 × 1000 m/sec. = 65 m/sec. 60 × 60 3 ∴ Speed = Distance Time ⇒ 65 = 800 + x 3 60
⇒ (800 + x ) × 3 = 65× 60
⇒ 800 + x = 65 × 20 m
⇒ x = 1300 – 800 = 500
∴ Length of tunnel = 500 metres.
Second Method :
Here, x = 800 m,
u = 78 km/hr= 78 5 = 65 m/sec 18 3
t = 1 min = 60 sec, y = ?
usingt = x + y u 60 = 800 + y 65 3 60 × 65 = 800 + y 3
1300 – 800 = y
y = 500 metres
 A train 300 metres long is running at a speed of 25 metres per second. It will cross a bridge of 200 metres in

 5 seconds
 10 seconds
 20 seconds
 25 seconds

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In crossing the bridge, the train travels its own length plus the length of the bridge.
Total distance (length)
= 300 + 200 = 500 m.
Speed = 25m/sec.
∴ The required time
= 500 ÷ 25 = 20 seconds
Second Method :
Here, x = 300m, y= 200 m, t = ?
u= 25 m/sect = x + y u = 300 + 200 25 = 500 25
t = 20 secondsCorrect Option: C
In crossing the bridge, the train travels its own length plus the length of the bridge.
Total distance (length)
= 300 + 200 = 500 m.
Speed = 25m/sec.
∴ The required time
= 500 ÷ 25 = 20 seconds
Second Method :
Here, x = 300m, y= 200 m, t = ?
u= 25 m/sect = x + y u = 300 + 200 25 = 500 25
t = 20 seconds