A train running at 10km/h leaves a railway station 45 hours later than another train, and meets it in 5 hours. What is the speed of the other train?
Let the speed of the train be v km/h. Distance travelled by this train in (5 + 45) hours = 50v km. Equating this to the distance travelled by the second train we get 50v = 10 × 5, which gives v = 1 km/h.