Question

On a 60km track, a train travel the first 30km at a uniform speed of 30km/h. How fast must the train travel the next 30km so as to average 40km/h for the entire trip? 

Answer 1

To do this get the totalt time taken for the trip:

Average speed= total distance/total time taken

So time. Comes out to be 1.5 hrs.

1 hrs was travelled at 30kmph to cever 30km.

So remainder of 30 km have to be covered at x speed to cover in .5hrs.

Speed=distance/time

Speed=30/.5

Speed=60kmph.

Answer 2

hope this answer will help you