A man travels a certain distance at km/h and returns the same way at km/h. What is his average speed for the whole trip (in km/h)?
Answer and explanation
Correct answer: D. 24
- Step 1: For equal round-trip distances covered at speeds and , the average speed is given by the harmonic mean: .
- Step 2: Substitute and : .
- Step 3: Divide the terms to determine the average speed: .
Answer
24.
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