Question

the train travels the first 30km of 120 km track with uniform speed of 30km/hr.What should be speed of the train To cover the remaining distance of the track so that is its average speed is 60 km/ hr for entire trip?

Answer 1

Answer:

Step-by-step explanation:

distance d1 = 30 km,      v1 = 30 kmph  

=> time taken = t1 = d1/v1 = 1 hour

So distance remaining = d2 = 120 - d1 = 90 km

let speed to cover distance d2 = v2  kmph  

=> time taken = d2/v2 = 90/v2  hours

average speed = total distance / total duration of time              

60 kmph = 120 km / [1 hour + 90 / v2  hours]    

 =>  1 = 2 / [ 1 + 90 / v2 ]       =>  v2 =90kmph ====================================

Answer 2

Answer:

The speed of the train should be 90 km/hr to cover the remaining distance of the track so that its average speed is 60 km/hr for the entire trip.

Step-by-step explanation:

Let the 30 km/hr speed be V1

and, another speed be V2

Average Speed = V1 + V2 / 2

60 = 30 + V2 / 2 => 120 = 30 + V2

=> V2 = 120 - 30 = 90{answer}.

VERIFICATION:

Average speed = V1 + V2 / 2

=> 60 = 30 + 90 / 2

=> 60 = 120 / 2 => 60 = 60 {verified}.

THIS WAS A SIMPLE PROCESS. SO,

PLEASE SELECT MY ANSWER AS THE BRAINLIEST ANSWER.