Question
A person is travelling 500 km, partly by car and partly by
train. The speed of the car is 70 km/h and train is 100 km/h. If the person drives for 55% of the distance, find the average speed of the complete journey (round off to the nearest whole number).Solution
ATQ,
Time taken by car = (0.55 × 500) / 70 = 275 / 70 ≈ 3.93 hours
Time taken by train = (0.45 × 500) / 100 = 225 / 100 = 2.25 hours
Average speed = 500 / (3.93 + 2.25) = 500 / 6.18 ≈ 81 km/h
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