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A car travels 60 km/h for 2 hours and 80 km/h for 3 hours. The AVERAGE SPEED for the entire trip is:
A70 km/h
B72 km/h
C68 km/h
D74 km/h
Answer & Solution
Correct answer: B. 72 km/h
Total distance = 60×2 + 80×3 = 120 + 240 = 360 km. Total time = 2 + 3 = 5 hr. Average speed = 360/5 = 72 km/h. (Not the simple average (60+80)/2 = 70 — because more time was spent at the higher speed.)
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