Question

A train sets off from A at 4 P.M. at the speed of 40 km/hr. Another train sets off from A at 5:00 P.M. at the speed of 60km/hr in the same direction. At what time will the second train catch up with the first train?

Answer 1

Answer:

1. let the distance at which the trains catch up be x km from point A.
2. let the time required for first train to cover x distance be y hours
3. so time required by second train will be (y-1) hrs
4. now speed = distance / time

so distance= speed × time

distance for both trains is same= x

5. speed of first train 40km/h

speed of second train is 60 km/h

6. so according to formula distance =speed x time

so 40 × y = 60 × (y-1)

40y= 60y -60

20y= 60

y = 3 hrs

so trains will catch up after 3hrs travel of first train i.e. at 4p.m. + 3 hrs = 7 p.m.