If a train runs at 40 km/hr, it reaches its destination late by 11 minutes, but if it runs at 50 km/hr, it is late by 5 minutes only. The correct time for the train to complete the journey is

Question: If a train runs at 40 km/hr, it reaches its destination late by 11 minutes, but if it runs at 50 km/hr, it is late by 5 minutes only. The correct time for the train to complete the journey is -

Solution:
Let the correct time for the train to complete the journey is x min
Then train cover distance in x + 11 minutes at speed 40 km/hr = 40(x + 11)​ km
Then train cover distance in x + 5 minutes at speed 50 km/hr = 50(x + 5) ​km

Now,
⇒ 40x + 440 = 50x + 250
⇒ 10x = 190
⇒ x = 19 minutes