Given: Speed of the car is 60km/hr and time taken by the car is 12 hours
Distance = Speed × Time
Thus, Distance covered by the car is 60 × 12 = 720 km
For the journey to be completed in 10 hours,
Speed = Distance/time = 720 / 10 = 72 km/h
Hence, new speed = 72 km/h
So, the difference in the speed = (72 - 60) km/hr = 12 km/hr