A train covered a

Let the speed of train be ‘s’, scheduled time be ‘t’ and distance be ‘d’.

Speed = distance/time

Given, covered a certain distance at a uniform speed. If the train could have been 10 km/hr. faster, it would have taken 2 hours less than the scheduled time. And, if the train were slower by 10 km/hr, it would have taken 3 hours more than the scheduled time.

⇒ d = st ------- (1)

d = (s + 10)(t – 2) ------ (2)

d = (s – 10)(t + 3) ------ (3)

Solving the above three equation we get, d = 600km, s = 50 km/hr and t = 12 hours