Problems based on trains running on parallel track

There are two trains running on two parallel tracks. Length of each train is 120 m. When they are running in opposite directions, they cross each other in 4 seconds and when they are running in the same direction they cross in 12 seconds. What is the speed of the faster train?

The graph shows position as a function of time for two trains running on parallel tracks. Which statement is true ?

Train X running at 50 km h leaves station A at 11 a.m and train Y running at 90 km/h on parallel tracks leaves station A at 3 p.m. on the same day and in the same direction. After what distance from station A will both the trains be together?

Train A and train B are running on parallel trackes in the opposite directions with speeds of 36 km/ hour and 72 km / hour respectively . A person is walking in train A in the direction opposite to its motion with a speed of 1.8 km / hour. Speed ("in" ms^(-1)) of this person as observed from train B will be close to : (take the distance between the tracks as negligible )

Train A and train B are running on parallel trackes in the opposite directions with speeds of 36 km/ hour and 72 km / hour respectively . A person is walking in train A in the direction opposite to its motion with a speed of 1.8 km / hour. Speed ("in" ms^(-1)) of this person as observed from train B will be close to : (take the distance between the tracks as negligible )

Two trains, 230m and 270m long, are running on parallel tracks in the oppoite directions at a speed of 40km/h and 50 km/h, respectively. What is the time taken by the trains to cross each other completely?

two trains A and B ,each of length 100 m , are running on parallel tracks. One overtakes the other in 20 s and one cross the other in 10 s. calculate the velocities of each train.

Two trains, each of length 200 m are running on parallel tracks. One overtakes the other is 20 s and one crosses the other in 10 s. The velocities of the two trains are