The odometer on a car goes to up 100,000 miles. The present owner of a car bought it when the odometer read 43,179 miles. He now wants to sell it: when you examine the car for possible purchase, you notice that the odometer reads 89,697 miles. What can you conclude about how many miles he drove the car, assuming that the odometer always worked correctly?
The odometer will count 100,000 and then reset the initial value and count again.
So,if car had actually travelled p kilometers present reading would be p(mod 100,000)
So,what we have to do is the difference in reading d.