Speed, Time and Distance


  1. A train passes two bridges of lengths 500 m and 250 m in 100 seconds and 60 seconds respectively. The length of the train is :
    1. 152 m
    2. 125 m
    3. 250 m
    4. 120 m

  1. View Hint View Answer Discuss in Forum

    Length of train = x metre (let)

    Speed of train
    =
    (Length of train and bridge)
    Time taken in crossing

    ⇒ 
    x + 500
    =
    x + 250
    10060

    ⇒ 
    x + 500
    =
    x + 250
    53

    ⇒  5x + 1250 = 3x + 1500
    ⇒  5x – 3x = 1500 – 1250
    ⇒  2x = 250
    ⇒  x =
    250
    = 125 metre
    2

    Correct Option: B

    Length of train = x metre (let)

    Speed of train
    =
    (Length of train and bridge)
    Time taken in crossing

    ⇒ 
    x + 500
    =
    x + 250
    10060

    ⇒ 
    x + 500
    =
    x + 250
    53

    ⇒  5x + 1250 = 3x + 1500
    ⇒  5x – 3x = 1500 – 1250
    ⇒  2x = 250
    ⇒  x =
    250
    = 125 metre
    2


  1. A 200 metre long train is running at a speed of 72 km/hr. How long will it take to cross 800metre long bridge ?
    1. 50 seconds
    2. 40 seconds
    3. 60 seconds
    4. 30 seconds

  1. View Hint View Answer Discuss in Forum

    Speed of train = 72 kmph

    =
    72 × 5
    m/sec.
    18

    = 20 m/sec.
    Required time
    =
    Length of train and bridge
    Speed of train

    =
    (200 + 800)
    20

    =
    1000
    = 50 seconds
    20

    Correct Option: A

    Speed of train = 72 kmph

    =
    72 × 5
    m/sec.
    18

    = 20 m/sec.
    Required time
    =
    Length of train and bridge
    Speed of train

    =
    (200 + 800)
    20

    =
    1000
    = 50 seconds
    20



  1. If a man running at 15 kmph crosses a bridge in 5 minutes, the length of the bridge is
    1. 1000 metres
    2. 500 metres
    3. 750 metres
    4. 1250 metres

  1. View Hint View Answer Discuss in Forum

    Time = 5 minutes

    =
    1
    hour
    12

    ∴  Length of bridge = Speed × Time
    = 15 ×
    1
    =
    5
    km.
    124

    =
    5
    × 1000metre
    4

    = 1250 metre

    Correct Option: D

    Time = 5 minutes

    =
    1
    hour
    12

    ∴  Length of bridge = Speed × Time
    = 15 ×
    1
    =
    5
    km.
    124

    =
    5
    × 1000metre
    4

    = 1250 metre


  1. How many seconds will a train 120 metre long running at the rate of 36 km/hr take to cross a bridge of 360 metres in length ?
    1. 48 sec
    2. 40 sec
    3. 46 sec
    4. 36 sec

  1. View Hint View Answer Discuss in Forum

    Speed of train = 36 kmph

    =
    36 × 5
    m/sec.
    18

    = 10 m/sec
    Required time
    =
    Length of train and bridge
    Speed of train

    =
    120 + 360
    =
    480
    = 48 seconds
    1010

    Correct Option: A

    Speed of train = 36 kmph

    =
    36 × 5
    m/sec.
    18

    = 10 m/sec
    Required time
    =
    Length of train and bridge
    Speed of train

    =
    120 + 360
    =
    480
    = 48 seconds
    1010



  1. A train 50 metre long passes a platform 100 metre long in 10 seconds. The speed of the train in km/hr is
    1. 10
    2. 54
    3. 15
    4. 100

  1. View Hint View Answer Discuss in Forum

    Speed of train =
    Length of platform and train
    Time taken to crossing

    =
    100 + 50
    metre/second
    10

    = 15 metre/second
    = 15 ×
    18
    kmph
    5

    = 54 kmph

    Correct Option: B

    Speed of train =
    Length of platform and train
    Time taken to crossing

    =
    100 + 50
    metre/second
    10

    = 15 metre/second
    = 15 ×
    18
    kmph
    5

    = 54 kmph