Speed, Time and Distance


  1. A train is moving at a speed of 80 km/h and covers a certain distance in 4.5 hours. The speed of the train to cover the same distance in 4 hours is
    1. 100 km/h
    2. 70 km/h
    3. 85 km/h
    4. 90 km/h

  1. View Hint View Answer Discuss in Forum

    Distance = Speed × Time
    = 80 × 4.5 = 360 km

    ∴   Required speed =
    360
    = 90 kmph.
    4

    Correct Option: D

    Distance = Speed × Time
    = 80 × 4.5 = 360 km

    ∴   Required speed =
    360
    = 90 kmph.
    4


  1. Two trains are running 40 km/hr and 20 km/hr respectively in the same direction. The fast train completely passes a man sitting in the slow train in 5 seconds. The length of the fast train is
    1. 23
      2
      m
      9
    2. 27 m
    3. 27
      7
      m
      9
    4. 23 m

  1. View Hint View Answer Discuss in Forum

    Relative speed = 40 – 20 = 20 km/hour

    =
    20 × 5
    m/sec.
    18

    ∴   Length of the faster train =
    20 × 5
    × 5 metres
    18

    =
    250
    = 27
    7
    metres
    99

    Correct Option: C

    Relative speed = 40 – 20 = 20 km/hour

    =
    20 × 5
    m/sec.
    18

    ∴   Length of the faster train =
    20 × 5
    × 5 metres
    18

    =
    250
    = 27
    7
    metres
    99



  1. A policeman goes after a thief who has 100 metres start, if the policeman runs a kilometre in 8 min, and the thief a km in 10 min, the distance covered by thief before he is over-powered is
    1. 350 m
    2. 400 m
    3. 320 m
    4. 420 m

  1. View Hint View Answer Discuss in Forum

    Relative speed =
    1000
    1000
    810

    =
    5000 − 4000
    =
    1000
    m/minute
    4040

    ∴  Required time =
    100
    1000
    40

    =
    4000
    = 4 m/minute
    1000

    ∴   Distance covered by the thief =
    1000
    × 4
    10

    = 400 metres

    Correct Option: B

    Relative speed =
    1000
    1000
    810

    =
    5000 − 4000
    =
    1000
    m/minute
    4040

    ∴  Required time =
    100
    1000
    40

    =
    4000
    = 4 m/minute
    1000

    ∴   Distance covered by the thief =
    1000
    × 4
    10

    = 400 metres


  1. A boy started from his house by bicycle at 10 a.m. at a speed of 12 km per hour. His elder brother started after 1 hr 15 mins by scooter along the same path and caught him at 1.30 p.m. The speed of the scooter will be (in km/hr)
    1. 4.5
    2. 36
    3. 18
      2
      3
    4. 9

  1. View Hint View Answer Discuss in Forum

    Let the speed of Scooter be x Distance covered by cycling in

    3
    1
    hours = Distance covered by scooter in
    2

    2
    1
    hours
    4

    ⇒  12 ×
    7
    = x ×
    9
    24

    ⇒  x =
    12 × 7 × 2
    9

    =
    56
    = 18
    2
    kmph
    33

    Correct Option: C

    Let the speed of Scooter be x Distance covered by cycling in

    3
    1
    hours = Distance covered by scooter in
    2

    2
    1
    hours
    4

    ⇒  12 ×
    7
    = x ×
    9
    24

    ⇒  x =
    12 × 7 × 2
    9

    =
    56
    = 18
    2
    kmph
    33



  1. Two trains start from a certain place on two parallel tracks in the same direction. The speed of the trains are 45 km/hr and 40 km/hr respectively. The distance between the two trains after 45 minutes will be
    1. 2 km 500 m
    2. 2 km 750 m
    3. 3 km 750 m
    4. 3 km 250 m

  1. View Hint View Answer Discuss in Forum

    Relative speed = 45– 40 = 5 kmph

    ∴  Required distance = 5 ×
    45
    km
    60

    =
    15
    km = 3 km 750
    4

    Correct Option: C

    Relative speed = 45– 40 = 5 kmph

    ∴  Required distance = 5 ×
    45
    km
    60

    =
    15
    km = 3 km 750
    4