Averages Q.4

0. The average speed of a taxi car from Town A to Town B is 35 kmph and return journey is 42 kmph. What is the average speed of the whole journey?

  • Option : C
  • Explanation : As the distance is not mentioned, L.C.M. of 35 and 42, that is, 210 can be assumed to be the total distance.
    Time taken from A to B = 210/35 = 6 hours
    Time taken from B to A= 210/42 = 5 hours
    Total Time taken = 11 hours
    Average speed = (210 + 210)/(6 + 5) = 420/11 = 38.17 kmph
    Alternatively, by applying direct formula
    = 2xy/(x+y)
    = (2*35*42)/35+42 = 38.17kmph
Cancel reply

Your email address will not be published. Required fields are marked *


Cancel reply

Your email address will not be published. Required fields are marked *