Speed, Time and Distance


  1. A train, 200 metre long, is running at a speed of 54 km/hr. The time in seconds that will be taken by train to cross a 175 metre long bridge is :
    1. 12.5
    2. 20
    3. 25
    4. 10

  1. View Hint View Answer Discuss in Forum

    Speed of train = 54 kmph

    =
    54 × 5
    m/sec.
    18

    = 15 m/sec.
    ∴  Required time =
    Length of train and bridge
    Speed of train

    =
    200 + 175
    seconds
    15

    =
    375
    seconds
    15

    = 25 seconds

    Correct Option: C

    Speed of train = 54 kmph

    =
    54 × 5
    m/sec.
    18

    = 15 m/sec.
    ∴  Required time =
    Length of train and bridge
    Speed of train

    =
    200 + 175
    seconds
    15

    =
    375
    seconds
    15

    = 25 seconds


  1. A train, 500 metre long, running at a uniform speed, passes a station in 35 seconds. If the length of the platform is 221 metre, the speed of the train in km/hr is
    1. 72
      1
      35
    2. 74.16
    3. 24.76
    4. 78.54

  1. View Hint View Answer Discuss in Forum

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

    =
    221 + 500
    metre/second
    35

    =
    721
    metre/second
    35

    =
    721 × 18
    kmph
    35 × 5

    = 74.16 kmph

    Correct Option: B

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

    =
    221 + 500
    metre/second
    35

    =
    721
    metre/second
    35

    =
    721 × 18
    kmph
    35 × 5

    = 74.16 kmph



  1. The lengths of a train and that of a platform are equal. If with a speed of 90 km/hr the train
    crosses the platform in one minute, then the length of the train (in metres) is
    1. 500
    2. 600
    3. 750
    4. 900

  1. View Hint View Answer Discuss in Forum

    Let, length of train = length of platform = x metre
    Speed of train = 90 kmph

    =
    90 × 5
    m/sec.
    18

    = 25 m/sec.
    ∴  Speed of train =
    Length of platform and train
    Time taken in crossing

    ⇒  25 =
    2x
    ⇒ 2x = 25 × 60
    60

    ⇒  x =
    25 × 60
    = 750 metre
    2

    Correct Option: C

    Let, length of train = length of platform = x metre
    Speed of train = 90 kmph

    =
    90 × 5
    m/sec.
    18

    = 25 m/sec.
    ∴  Speed of train =
    Length of platform and train
    Time taken in crossing

    ⇒  25 =
    2x
    ⇒ 2x = 25 × 60
    60

    ⇒  x =
    25 × 60
    = 750 metre
    2


  1. A moving train passes a platform 50 metre long in 14 seconds and a lamp post in 10 seconds. The speed of the train (in km/h) is :
    1. 24
    2. 36
    3. 40
    4. 45

  1. View Hint View Answer Discuss in Forum

    Let the length of train be x metre.
    When a train crosses a platform, distance covered by it = length of train and platform.

    ∴  Speed of train =
    x + 50
    =
    x
    1410

    ⇒ 
    x + 50
    =
    x
    75

    ⇒  7x = 5x + 250
    ⇒  7x – 5x = 250
    ⇒ 2x = 250 ⇒ x =
    250
    = 125 metre
    2

    ∴ Speed of train =
    x
    10

    =
    125
    m./sec.
    10

    =
    125
    ×
    18
    kmph
    105

    = 45 kmph

    Correct Option: D

    Let the length of train be x metre.
    When a train crosses a platform, distance covered by it = length of train and platform.

    ∴  Speed of train =
    x + 50
    =
    x
    1410

    ⇒ 
    x + 50
    =
    x
    75

    ⇒  7x = 5x + 250
    ⇒  7x – 5x = 250
    ⇒ 2x = 250 ⇒ x =
    250
    = 125 metre
    2

    ∴ Speed of train =
    x
    10

    =
    125
    m./sec.
    10

    =
    125
    ×
    18
    kmph
    105

    = 45 kmph



  1. A train 150 metre long takes 20 seconds to cross a platform 450 metre long. The speed of the train in, km per hour, is :
    1. 108
    2. 100
    3. 106
    4. 104

  1. View Hint View Answer Discuss in Forum

    Speed of train =
    length of platform and train
    Time taken in crossing

    =
    450 + 150
    m/sec.
    20

    =
    600
    m/sec.
    20

    = 30 ×
    18
    kmph
    5

    = 108 kmph.

    Correct Option: A

    Speed of train =
    length of platform and train
    Time taken in crossing

    =
    450 + 150
    m/sec.
    20

    =
    600
    m/sec.
    20

    = 30 ×
    18
    kmph
    5

    = 108 kmph.