Multiple choice

Yamini goes from Ambala to Delhi covering a distance of 245 km in 4 hours and comes back to Ambala in 3 hours. What is the average speed of Yamini?

  1. 122.5 kmph

  2. 70 kmph

  3. 81.67 kmph

  4. 90 kmph
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total distance = 245 + 245 = 490 km. Total time = 4 + 3 = 7 hours. Average speed = 490 / 7 = 70 kmph.

AI explanation

The average speed for an entire journey when the distances covered are equal in both directions is given by the formula 2xy divided by (x + y), where x is the speed going and y is the speed returning. The speed from Ambala to Delhi is 245 divided by 4, equaling 61.25 kmph, and the speed from Delhi to Ambala is 245 divided by 3, equaling 81.67 kmph. Plugging these into the formula gives (2 times 61.25 times 81.67) divided by (61.25 plus 81.67), which simplifies to 10004.575 divided by 142.92, resulting in an average speed of 70 kmph.

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