Question
Amit travels the first 20% of his journey at a constant
speed of 40 km/h and covers the remaining 320 km at a constant speed of 32 km/h. What is his average speed for the entire journey?Solution
ATQ,
Total journey = 320 ÷ 0.8 = 400 km
Average speed = Total distance covered ÷ Total time taken
Time taken to cover 20% of the journey = {(400 × 0.2)/40} = 2 hours
Time taken to cover the remaining journey = (320/32) = 10 hours
So, average speed = 400/12 ~ 33.33 km/h
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