two trains 200 meters and 150 meters are running on the parallel rails at this rate of 40km/hr and 45km/hr.in how much time will they cross each other if they are running in the same direction
40h + 0.2 = 45h + 0.15
5h = 0.05
h = 0.01
0.01 * 60 * 60 = 36 seconds
I think you mean this...
The 150m train starts at the back of the 200m train but moves 5kmh faster. For how long are they overlapping?
They're overlapping For 350 metres (The 200m to get the front of the faster train to the front of the other train, then the 150m to get the back of the faster train in front of the front of the slower train).
Every hour, the faster train catches up 5km on the slower one. How long does it take to catch up 0.35 km on it?
(0.35/5) * 60 = 4.2 minutes = 252 seconds.