Multiple choice

Avinash travels first one-third of the total distance at the speed of 10 kmph and the next one-third distance at the speed of 20 kmph and the last one-third distance at the speed of 60 kmph. What is the average speed of Avinash?

  1. 18

  2. 19

  3. 16

  4. 12

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Avinash travels three equal distances (let each = d) at speeds 10, 20, 60 kmph. Total distance = 3d. Total time = d/10 + d/20 + d/60 = d(1/10 + 1/20 + 1/60) = d(6/60 + 3/60 + 1/60) = d(10/60) = d/6 hours. Average speed = total distance / total time = 3d / (d/6) = 18 kmph. Option A is correct.

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