An auto rickshaw takes 3 hours to cover a distance of 36 km. If its speed is increased by 4 km/h, the time taken by it to cover the same distance is __________.
Distance covered by auto rickshaw in 3 hours = 36km
Speed = 36/3 = 12 km/hr
If we increase the speed by 4km/hr, then the total speed becomes = 12+4 = 16km/hr
Now, the time taken by auto rickshaw will be = 36/16 = (36×60)/16 = 135 min
= 120 + 15
= 2 hour 15min