Speed, Time and Distance


  1. If a train runs at 5/6 of its original speed, then it reaches the station 10 min late. Then find out the usual time taken by train to cover the distance.









  1. View Hint View Answer Discuss in Forum

    Assume the actual speed of train be x and actual time taken be y

    And, distance is same in both case

    Correct Option: C

    Let the actual speed of train be x and actual time taken be y

    Then new speed of train = 5x/6

    Therefore, new time taken = 6y/5 (as distance is same in both case)

    Given, 6y/5 - y = 1/6 hr , therefore actual time = 50 min


  1. A car is moving with the speed of 47.52km/hr and the radius of the wheel of car is 21 cm. Calculate the approximate number of revolutions made by the wheel in one minute.









  1. View Hint View Answer Discuss in Forum

    Circumference of circle = 2πr
    Where r = radius of circle

    Correct Option: C

    Speed in cm/minute = (Speed in km/hr x 1000 x100 )/60
    = 47.52x(50/3)
    =79200 cm/min

    And Circumference of circle = 2πr
    =2 x ( 22 / 7 ) x 21
    =132

    No. of revolutions = ( Speed in cm/minute ) / circumference of circle in cm
    =79200 / 132
    =600 rpm



  1. A man walking at 3km/hr crosses a square field diagonally in 2 min. The area of the field is ?









  1. View Hint View Answer Discuss in Forum

    speed = 3 x ( 5/18 ) m/sec.
    = 5 / 6 m/sec.

    ∴ Distance covered in 2 min. = ( 5 / 6) x 2 x 60 m
    = 100 m.

    ∴ Length of diagonal = 100 m

    Correct Option: C

    speed = 3 x ( 5/18 ) m/sec.
    = 5 / 6 m/sec.

    ∴ Distance covered in 2 min. = ( 5 / 6) x 2 x 60 m
    = 100 m.

    ∴ Length of diagonal = 100 m

    Area of the field = 1/2 x diagonal2
    =1/2 x 100 x 100 m2
    = 5000 m2
    = 50 acres.


  1. A certain distance is covered at a certain speed. If half of this distance is covered in double the time, the ratio of the two speed is ?









  1. View Hint View Answer Discuss in Forum

    Let x km . be covered in y hrs.
    then, 1st speed = (x / y) km/hr.

    2nd speed = [(x/2) / 2y)] km/hr.
    = (x/4y) km/hr.

    Correct Option: A

    Let x km . be covered in y hrs.
    then, 1st speed = (x / y) km/hr.

    2nd speed = [(x/2) / 2y)] km/hr.
    = (x/4y) km/hr.

    ∴ Ratio of speed = x/y : x/4y = 1 :1/4 = 4: 1



  1. A is twice as fast as B and B is thrice as fact as C is . The journey covered by C in 42 minute, will be covered by A in ?









  1. View Hint View Answer Discuss in Forum

    Let C' s speed = x km/hr.
    Then, B's speed = 3x km/hr.
    and A's speed = 6x km/hr.

    ∴ Ratio of speed of A, B, C
    = 6x : 3x : x = 6 : 3 : 1

    Ratio of times taken = 1/6 : 1/3 : 1 or 1 : 2 : 6

    Correct Option: D

    Let C' s speed = x km/hr.
    Then, B's speed = 3x km/hr.
    and A's speed = 6x km/hr.

    ∴ Ratio of speed of A, B, C
    = 6x : 3x : x = 6 : 3 : 1

    Ratio of times taken = 1/6 : 1/3 : 1 or 1 : 2 : 6

    ∵ 6 : 1 : : 42 : t
    ⇒ 6t = 42
    ⇒ t = 7 min.