Speed, Time and Distance


  1. A train travelled at a speed of 35 km/hr for the first 10 minutes and at a speed of 20 km/hr for the next 5 minutes. The average speed of the train for the total 15 minutes is









  1. View Hint View Answer Discuss in Forum

    Distance covered = 35 ×
    10
    + 20 ×
    5
    km
    6060

    =
    35
    +
    10
    km
    66

    =
    45
    km
    6

    Total time = 15 minutes
    =
    1
    hour
    4

    ∴  Required average speed =
    Distance covered
    Time taken

    =
    45
    × 4
    6

    = 30 kmph

    Correct Option: A

    Distance covered = 35 ×
    10
    + 20 ×
    5
    km
    6060

    =
    35
    +
    10
    km
    66

    =
    45
    km
    6

    Total time = 15 minutes
    =
    1
    hour
    4

    ∴  Required average speed =
    Distance covered
    Time taken

    =
    45
    × 4
    6

    = 30 kmph


  1. A bus covers four successive 3 km stretches at speed of 10 km/hr, 20 km/hr, 30 km/hr and 60 km/hr respectively. Its average speed over this distance is









  1. View Hint View Answer Discuss in Forum

    Average speed =
    Total distance
    Time taken

    =
    12
    3
    +
    3
    +
    3
    +
    3
    10203060


    =
    12
    3
    6 + 3 + 2 + 1
    60

    =
    12 × 60
    = 20 kmph
    3 × 12

    Correct Option: C

    Average speed =
    Total distance
    Time taken

    =
    12
    3
    +
    3
    +
    3
    +
    3
    10203060


    =
    12
    3
    6 + 3 + 2 + 1
    60

    =
    12 × 60
    = 20 kmph
    3 × 12



  1. With an average speed of 40 km/hr, a train reaches its destination in time. If it goes with an average speed of 35 km/hr, it is late by 15 minutes. The total journey is









  1. View Hint View Answer Discuss in Forum

    Let the length of journey be x km, then

    x
    x
    =
    15
    =
    1
    3540604

    ⇒ 
    8x − 7x
    =
    1
    2804

    ⇒  x =
    280
    = 70 km
    4

    Correct Option: C

    Let the length of journey be x km, then

    x
    x
    =
    15
    =
    1
    3540604

    ⇒ 
    8x − 7x
    =
    1
    2804

    ⇒  x =
    280
    = 70 km
    4


  1. P travels for 6 hours at the rate of 5 km/ hour and for 3 hours at the rate of 6 km/ hour. The average speed of the journey in km/ hour is









  1. View Hint View Answer Discuss in Forum

    Total distance
    = 5 × 6 + 3 × 6
    = 30 + 18 = 48 km
    Total time = 9 hours

    ∴ Average speed =
    48
    =
    16
    = 5
    1
    kmph
    933

    Correct Option: B

    Total distance
    = 5 × 6 + 3 × 6
    = 30 + 18 = 48 km
    Total time = 9 hours

    ∴ Average speed =
    48
    =
    16
    = 5
    1
    kmph
    933



  1. A man covers the journey from a station A to station B at a uniform speed of 36 km/hr and
    returns to A with a uniform speed of 45 km/hr. His average speed for the whole journey is :









  1. View Hint View Answer Discuss in Forum

    Here same distances are covered at different speeds.

    ∴  Average speed =
    2xy
    kmph
    x + y

    =
    2 × 36 × 45
    kmph
    (36 + 45)

    =
    2 × 36 × 45
    = 40 kmph
    81

    Correct Option: A

    Here same distances are covered at different speeds.

    ∴  Average speed =
    2xy
    kmph
    x + y

    =
    2 × 36 × 45
    kmph
    (36 + 45)

    =
    2 × 36 × 45
    = 40 kmph
    81