Multiple choice

A person started a journey from point A at 25 km/hr and reached point B. Then, he travelled back from B to A at 35 km/hr. Find his average speed over the entire journey.

  1. 26 km/hr

  2. 27.25 km/hr

  3. 29.17 km/hr

  4. 31.1 km/hr

  5. 32 km/hr
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C Correct answer
Explanation

Average speed for a round trip with speeds v1 and v2 is given by (2 * v1 * v2) / (v1 + v2). Here, (2 * 25 * 35) / (25 + 35) = 1750 / 60 = 29.166... which rounds to 29.17 km/hr.

AI explanation

Since the person travels equal distances at two different speeds, apply the average speed formula for equal distances, which is twice the product of the two speeds divided by their sum. Calculate this as two multiplied by 25 multiplied by 35, divided by the sum of 25 and 35, giving 1750 divided by 60. This yields a result of 29.17 kilometers per hour.

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