Question

On a 120 km track, a train travels the first 30km at a uniform speed of 30 km/h. How fast must the train travel the next 90km so that the average speed becomes 60 km/h for the entire journey?

Answer 1

Explanation:

average speed =total distance /total time

60=120/t

so, t=2hr

t for first 30 km=distance/speed

=30/30=1hr

so, for remaining 90km speed =distance /time

=90km/1hr

=90km/h

Answer 2

Answer:

Here is your answer

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