Explanation

Let's use this fundamental formula of

Distance = speed * time

By this, we get the speed of the train as (60/1.5)= 40 kmph

Since nothing is mentioned, assuming the train travels with the same speed ( I.e the speed is being assumed along the journey)

20/60 because 1 hour = 60 minutes. This means 20 minutes can be written as 0.3333 hours

Time = 20min = 0.3hr

Distance traveled = speed x time

Thereby, Distance is (40 x 0.3) = 12 km

ND16-8-2023