IBPS Clerk Prelims Model Paper 22

Brown overtakes John in 4 hours.
This means that he can cover 4 × 20 = 80 km in this time.
That means in 2 hours before Brown starts, John has covered 80 km
So, John’s speed is 40 kmph and that of Brown is 60 kmph
So, the distance travelled by Brown = 60 × 4 = 240 km