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 = 72km/h

So, the difference in the speed = (72 - 60) km/hr = 12km/hr