Question
A car travels 60 km at a speed of 30 km/hr, then 90 km
at a speed of 45 km/hr, and finally 80 km at a speed of 40 km/hr. Find the average speed of the car for the entire journey.Solution
Total distance = 60 + 90 + 80 = 230 km. Time for 60 km = 60 / 30 = 2 hours, for 90 km = 90 / 45 = 2 hours, and for 80 km = 80 / 40 = 2 hours. Total time = 2 + 2 + 2 = 6 hours. Average speed = Total distance / Total time = 230 / 6 ≈ 38.33 km/hr. Answer: b) 38.33 km/hr
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