Speed, Time and Distance


  1. The time taken by a train 160 m long, running at 72 km/hr, in crossing an electric pole is
    1. 8 seconds
    2. 9 seconds
    3. 6 seconds
    4. 4 seconds

  1. View Hint View Answer Discuss in Forum

    Distance covered in crossing a pole = Length of train
    Speed of train = 72 kmph

    =
    72 × 5
    m./sec.
    18

    = 20 m./sec.
    ∴  Required time =
    160
    20

    = 8 seconds

    Correct Option: A

    Distance covered in crossing a pole = Length of train
    Speed of train = 72 kmph

    =
    72 × 5
    m./sec.
    18

    = 20 m./sec.
    ∴  Required time =
    160
    20

    = 8 seconds


  1. A train 150m long passes a km stone in 30 seconds and another train of the same length travelling in opposite direction in 10 seconds. The speed ot the second train is :
    1. 90 km/hr
    2. 125 km/hr
    3. 25 km/hr
    4. 75 km/hr

  1. View Hint View Answer Discuss in Forum

    ∴  Speed of train =
    150
    = 5 m/sec.
    30

    Speed of train B = x m/sec.
    Relative speed = (5+x) m/sec.
    ∴  Length of both trains = Relative speed × Time
    ⇒  300 = (5 + x) × 10
    ⇒  5 + x =
    300
    = 30
    10

    ⇒  x = 30 – 5 = 25 m/sec.
    =
    25 × 18
    kmph.
    5

    = 90 kmph.

    Correct Option: A

    ∴  Speed of train =
    150
    = 5 m/sec.
    30

    Speed of train B = x m/sec.
    Relative speed = (5+x) m/sec.
    ∴  Length of both trains = Relative speed × Time
    ⇒  300 = (5 + x) × 10
    ⇒  5 + x =
    300
    = 30
    10

    ⇒  x = 30 – 5 = 25 m/sec.
    =
    25 × 18
    kmph.
    5

    = 90 kmph.



  1. A train is 250m long. If the train takes 50 seconds to cross a tree by the railway line, then the speed of the train in km/hr is :
    1. 10
    2. 9
    3. 5
    4. 18

  1. View Hint View Answer Discuss in Forum

    Speed of train =
    Length of train
    Time taken in crossing

    =
    250
    = 5 m/sec.
    50

    = 5 ×
    18
    kmph.
    5

    = 18 kmph

    Correct Option: D

    Speed of train =
    Length of train
    Time taken in crossing

    =
    250
    = 5 m/sec.
    50

    = 5 ×
    18
    kmph.
    5

    = 18 kmph


  1. A train passes an electrical pole in 20 seconds and passes a platform 250 m long in 45 seconds. Find the length of the train.
    1. 400m
    2. 200m
    3. 300m
    4. 250m

  1. View Hint View Answer Discuss in Forum

    If the length of train be x metre,
    then speed of train

    =
    x
    =
    x + 250
    2045

    ⇒ 
    x
    =
    x + 250
    49

    ⇒  9x = 4x + 1000
    ⇒  9x – 4x = 1000
    ⇒  5x = 1000
    ⇒  x =
    1000
    = 200 metre
    5

    Correct Option: B

    If the length of train be x metre,
    then speed of train

    =
    x
    =
    x + 250
    2045

    ⇒ 
    x
    =
    x + 250
    49

    ⇒  9x = 4x + 1000
    ⇒  9x – 4x = 1000
    ⇒  5x = 1000
    ⇒  x =
    1000
    = 200 metre
    5



  1. If a man walks at the rate of 5 km/hour, he misses a train by 7 minutes. However if he walks at the rate of 6 km/hour, he reaches the station 5 minutes before the arrival of the train. The distance covered by him to reach the station is
    1. 6 km
    2. 7 km
    3. 6.25 km
    4. 4 km

  1. View Hint View Answer Discuss in Forum

    Let the required distance be x km.
    Difference of time = 7 + 5 = 12

    minutes =
    1
    hour
    5

    Time =
    Distance
    Speed

    According to the question,
    x
    x
    =
    1
    565

    ⇒ 
    6x − 5x
    =
    1
    305

    ⇒ 
    x
    =
    1
    305

    ⇒  x =
    30
    = 6 km.
    5

    Correct Option: D

    Let the required distance be x km.
    Difference of time = 7 + 5 = 12

    minutes =
    1
    hour
    5

    Time =
    Distance
    Speed

    According to the question,
    x
    x
    =
    1
    565

    ⇒ 
    6x − 5x
    =
    1
    305

    ⇒ 
    x
    =
    1
    305

    ⇒  x =
    30
    = 6 km.
    5