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A train covers the first 5 km of its journey at a speed of 30 km / hr and the next 15 km at a speed of 45 ~km / hr . What is the average speed of the train?

Options

  1. A35 ~km / hr
  2. B37.5 ~km / hr
  3. C39.5 ~km / hr
  4. D40 ~km / hr

Correct answer

D. 40 ~km / hr

Step-by-step solution

Time taken by train to cover first 5 ~km = Distance Speed = 5 30 = 1 6 hr Time taken by train to cover next 15 ~km = 15 45 = 1 3 hr . aligned & Average speed = 5+15 1 6 + 1 3 & = 20 1+2 6 = 120 3 =40 ~km / hr aligned

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