Multiple choice general knowledge math & puzzles

In a circular track of 100km A runs at 25 km/hr and B runs at 10 km/hr. In hw much time does a overtake b for the 3rd time.

  1. 20h

  2. 40h

  3. 8.57h(approx)

  4. none of these

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A and B run in the same direction. Their relative speed is $25 - 10 = 15$ km/hr. To overtake B for the third time, A must cover a relative distance of 3 laps, which is $3 \times 100 = 300$ km. The time taken is $300 / 15 = 20$ hours. Distractors represent incorrect relative speeds or lap counts.