0Average speed = Total distance / Total Time
Eg. A car travels at a speed of 40 kmph for the onward journey and 50 kmph for the return journey. What is the average speed ?
Ans) Let x be the distance travelled by the car for the onward and return journey each. So total distance is 2x kms.
Time = Distance / Speed
So time for the onward journey = x/40 hrs while time for the return journey = x/50 hrs
Total time = x/40 + x/50 = 9x/200 hrs
So Average speed = 2x / (9x/200) = 2/9 * 200 = 44.44 kmph
Remember, for such kind of problems do not simply take the average of onward and return journeys.
