A train leaves station x and travels east at 30 kph. Two hours later,another train leaves the same station and travels in the same direction on a parallel track at 45kph. At what point will the faster train overtake the slower train?

Answer 1

in 2 hours, the 1st train has covered 60 km.

the 2nd train goes 15km/hr faster, so it will take 60/15 = 4 hours to make up the distance.