Question

On a 120 km track, a train travels the first 30 km at a uniform speed of 30 km/h. How fast must the train travel the next 90 km so as to average speed for entire trip is 60 km/h?
(A) 60 km/h
(B) 40 km/h
(C) 90 km/h
(D) 120 km/h

Answer 1

Heyaa ❤️

Here's ur answer ☺️
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Total distance = 120 km
Average speed = 60 km/h

Total time = 120/ 60 = 2 hrs

Time me taken for the 1st 30 km = 30 km /30 km/h= 1 hrs

Hence, time remaining to cover the remaining 90 km = 2 hrs - 1 hrs = 1 hour

Speed during 90 km = 90 km/h
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Hope it helps ✌️