Question

A train travels the first letter kilometre of 120 km track with a uniform speed of 30 kilometre per hour what should be the distance of the train to cover the remaining distance of the track so that its speed is 60 km per hour for the entire trip​

Answer 1

First letter kilometres =120/30
40/ hr
Remaining distance =60/30
20/hr

Answer 2

Answer:

90 km

Explanation:

please see the following question and its ans  ,

Ques - 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 60 km/h for the entire trip ? ??

Ans - Speed of the train in the first 30 km, v1 = 30 km/h

Speed of the train in the next 90 km, v2 (to be determined)

Average speed = 60 km/h = (v1 + v2)/2  

                                         = (30 km/h + v2)/2  

⇒ v2 = 90 km/h

So , train travel the next 90 km so as to average 60 km/h for the entire trip is 90 kmph