Speed, Time and Distance


  1. A man goes uphill with an average speed of 35 km/hr, and covers down with an average speed of 45 km/hr. The distance travelled in both the cases being the same , the average speed for the entire journey is ?
    1. 38 3/8 km/hr.
    2. 39 3/8 km/hr.
    3. 40 km/hr
    4. None of these

  1. View Hint View Answer Discuss in Forum

    Average speed = 2uv / (u + v)

    Correct Option: B

    Average speed = 2uv / (u + v)
    = ( 2 x 35 x 45) / (35 + 45) km/hr.
    = 39 3/8 km/hr


  1. If a boy takes as much time in running 10 m as a car takes in covering 25 m, the distance covered by the boy during the time the car covers 1 km, is ?
    1. 400 m.
    2. 40 m.
    3. 250 m.
    4. 650 m.

  1. View Hint View Answer Discuss in Forum

    Let distance covered by boy is Y.
    Then, 25 : 10 : : 1000 : Y

    Correct Option: A

    Let distance covered by boy is Y.
    Then, 25 : 10 : : 1000 : Y
    ⇒ Y = (10 x 1000)/25 = 400 m



  1. The ratio between the rates of walking of A and B is 2:3 , if the time taken by B to cover a certain distance is 36 minutes, the time taken by A to cover that much distance is ?
    1. 24 min
    2. 54min
    3. 48 min
    4. 21.6min

  1. View Hint View Answer Discuss in Forum

    Ratio of speed = 2 : 3
    Ratio of times taken for same distance = 1/2 : 1/3
    From question 1/2 : 1/3 = t : 36

    Correct Option: B

    Ratio of speed = 2 : 3
    Ratio of times taken for same distance = 1/2 : 1/3
    From question 1/2 : 1/3 = t : 36
    ⇒ (1/3) x t = (1/2) x 36
    ∴ x = 54 min .


  1. A man, on tour travel first 160 km. at 64 km/hr. and the next 160 km. at 80 km/hr. The average speed for first 320 km. of the tour is ?
    1. 35.55 km/hr
    2. 71.11 km/hr
    3. 36 km/hr
    4. 72 km/hr

  1. View Hint View Answer Discuss in Forum

    Average speed = 2uv / ( u + v ) km/hr

    Correct Option: B

    Average speed = 2uv / ( u + v ) km/hr
    =(2 x 64 x 80) / (64 + 80) km/hr
    = (2 x 64 x 80) / 144 km/hr.
    = 71.11 km/hr



  1. By walking at 3/4 of his usual speed , a man reaches his office 20 minutes later than usual . this usual time is ?
    1. 30 minutes
    2. 60 minutes
    3. 75 minutes
    4. 1 hour 30 minutes

  1. View Hint View Answer Discuss in Forum

    At 3/4 of the usual speed, the time taken is 4/3 of the usual time
    ∴ 4/3 of usual time - usual time = 20 min

    Correct Option: B

    At 3/4 of the usual speed, the time taken is 4/3 of the usual time
    ∴ 4/3 of usual time - usual time = 20 min
    ⇒ 4x/3 - x = 20
    ⇒ x/3 = 20
    ∴ x = 60 min.