Speed, Time and Distance


  1. Two trains A and B travel from points X to Y and the ratio of the speeds of A to that of B is 2 : 7. Find the ratio of time taken by A and B to reach From X to Y.









  1. View Hint View Answer Discuss in Forum

    We know that speed is inversely proportional to time.
    Given that, (Speed of A ) : (speed of B ) = 2 : 7

    Correct Option: D

    We know that speed is inversely proportional to time.
    Given that, (Speed of A ) : (speed of B ) = 2 : 7
    ∴(Time taken by A ) : (Time taken by B ) = 1/2 : 1/7 = 7 : 2


  1. A man completes 30 km of a journey at 6 km/h and the remaining 40 km of the journey in 5 h. Find the average speed for the whole journey.









  1. View Hint View Answer Discuss in Forum

    Total distance = 30 + 40 = 70 km
    Total time taken = (30/6) + 5 = 10 h

    Correct Option: B

    Total distance = 30 + 40 = 70 km
    Total time taken = (30/6) + 5 = 10 h
    ∴ Required average speed = 70/10 = 7 km/h



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









  1. View Hint View Answer Discuss in Forum

    Let L km distance be covered in T h. So, speed in first case = L/T km/h.
    And speed in second case = (L/2)/2T = L/4T km/h

    Correct Option: A

    Let L km distance be covered in T h. So, speed in first case = L/T km/h.
    And speed in second case = (L/2)/2T = L/4T km/h
    ∴ Required ratio = L/T : L/4T =1 : 1/4 = 4 : 1


  1. Moving 6/7 of its usual speed a train is 10 min late. Find its usual time to cover the journey.









  1. View Hint View Answer Discuss in Forum

    New speed = 6/7 of usual speed
    Now, time taken = 7/6 of usual time
    (7/6 of the usual time) - (usual time) = 10 min

    Correct Option: D

    New speed = 6/7 of usual speed
    Now, time taken = 7/6 of usual time
    (7/6 of the usual time) - (usual time) = 10 min
    ⇒ 1/6 of the usual time = 10 min
    ∴ Usual time = 60 min



  1. John started from A to B and Vinod from B to A. If the distance betweeen A and B is 125 km and they meet at 75 km from A, what is the ratio of John's speed to that of Vinod's speed?









  1. View Hint View Answer Discuss in Forum

    John's speed : Vinod's speed = 75 : ( 125 - 75 )

    Correct Option: B

    John's speed : Vinod's speed = 75 : ( 125 - 75 )
    = 75 : 50 = 3 : 2