A car travels 100 km at 50 km/h, then 100 km at 100 km/h. Average speed:
A75 km/h
B66.67 km/h (harmonic mean for equal distances)
C60 km/h
D87.5 km/h
Answer & Solution
Correct answer: B. 66.67 km/h (harmonic mean for equal distances)
Time: 100/50 + 100/100 = 2 + 1 = 3 h. Distance 200 km. v_avg = 200/3 ≈ 66.67 km/h. (Harmonic mean for equal distances.)
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