Two train of length 100 meter and 80 meter respectively run on parallel lines of rails. When running in the same direction the faster train passed the slower one in 18 second, but when they are running in opposite directions with the same speed as earlier, they pass each other  in 9 seconds. Find the speed of each train.

How many seconds will a 500-meter-long train take to cross a man walking with a speed of 3 km/hr. in the direction of the moving train if the speed of the train is 63 km/hr? 

Two trains are moving in the same direction at speed of 54 km/h and 92 km/h, their lengths are 400 m and 360 m respectively. What is the time taken (in seconds) by faster train to cross the slower train?

Two towns A and B are 170 km apart, a train starts at 9 a.m. from A towards B at a speed of 40 km/hr, at 11 a.m. another train starts from B towards A at a speed of 50 km/hr. When will the two trains meet?

A train 270 meters long is running at a speed of 36 km per hour then it will cross a bridge of length 180 meters in : 

The Garibrath express can move at 45 km./hr. without its rake and the speed is diminished by a constant that varies as the square root of the number of wagons attached. If it is known that with 9 wagons, the speed is 30 km./hr., what is the greatest number of wagons with which the train can just move?