Question

The distance between Delhi and Agra is 200 kilometre. A train travels the first 100 kilometre at a speed of 50 kilometre per hour. How fast much the train travel the next 100 kilometre so as to average 70 kilometre per hour for the whole journey​

Answer 1

a train travels the first 100 km at a speed

of 50km per hour

so it's time given first 100km in 2h

and last 100km travels as a speed 70km per hour

so it's time given 1h and 42 min travels for 100km