Two trains start at the same time from Dehradun and Jaipur and proceed toward each other at the speed of 55 km/hr and 25 km/hr respectively. When they meet, it is found that one train has travelled 150 km more than the other. Find the distance between Dehradun and Jaipur.

Difference between speed of train from Dehradun and that of Jaipur = 30 km/hr That means train from Dehradun runs 30 km more than train from Jaipur in 1 hour. Therefore, train from Dehradun must have run 150 km more than train Jaipur in 5 hrs. That means both the trains have run for 5 hrs, when they met. Distance covered by train from Dehradun in 5 hrs = Speed × Time = 55 × 5 = 275 km. Distance covered by train from Jaipur in 5 hrs = Speed × Time = 25 × 5 = 125 km. Total Distance between train from Dehradun and Jaipur = 275km + 125km = 400 km.