Difficult Distance, Speed and time problems

1) A man takes 5 hrs and 45 mins to walk to a certain place and ride back. He would have gained 2 km by riding both ways. The time he would take to walk both ways is?

2) A jeep travels a distance of 100 km at a uniform speed. If the speed of the jeep is 5km/hr, then it takes 3 hrs to cover the same distance. Find the original speed of the jeep.

3) A train overtakes two men walking in the same direction as the train at the speed of 3km/hr and 4.5km/he in 8 and 12 sec respectively. Find the length of the train.