Two trains are moving in the same direction at the speed of 24 km/hr and 50 km/hr. The time taken by faster train to cross a man sitting in the slower train is 72 seconds. What will be the length (in metres) of the faster train?
A boat goes 15 km upstream and 10 1/2 km down stream in 3 hrs 15 min. It goes 12 km upstream and 14 km downstream in 3 hrs. What is the speed of the boat in still water?