A bus covers 630 km in 9 h. If it completes the first two thirds of the journey at 60 km/h, calculate its speed for the rest of the journey.
2/3 journey =23×630=2×210=420km
Time for 2/3 journey =distancespeed=42060=7hr
⇒ Time for rest of journey =2hr
⇒ Speed for rest of journey =Distancetime=2102=105km/n.