Answer: 112.5 km/h

Given parameters

Total time (t) = 19 hours

The train has completed journey of = 10 hours

The average speed of the train = 100km per hour

Let us calculate the total distance train has to travel

Total distance = Speed x time

Total distance = 19 hours x 100 km/hrs

Total distance = = 1900 km

The distance covered by the train in 10 hours is

⇒ 10 hours x 100 km/hrs

⇒ 1,000 km

Because of the distribution of rail traffic the waiting time is 1 hour.

Total travelling time = 10 hours travelling + 1 hour waiting time

∴ Total travelling time = 11 hours

The distance covered by the time during the duration of 11 hours is 1,000km

Let us calculate the time left to reach the destination

⇒ 19 hours – 11 hours

⇒ 8 hours

So the distance to be covered in 8 hours = 1900 km -1000 km

The distance to be covered in 8 hours = 900 km

Speed necessary to reach on same time = Balance Distance / balance Time

Speed necessary to reach on same time = 900km / 8 hours

Speed necessary to reach on same time = 112.5 km/h

In order to complete the journey at the same time the train should achieve a speed of 112.5 km/h to cover the 1-hour delay.