Saul was driving to work one day, when he glanced at his car's dashboard and noticed something interesting about his mileage indicators. His odometer, which shows the miles driven since the car was manufactured, hit 12,345.6 miles, and his trip meter read 123.4 miles. So, the meter matches the first four digits on the odometer.
(i) How far must Saul drive - before this happens again?
(ii) What is the smallest distance that Saul can drive so that the two odometers have all ten digits between them, but share no digits in common?
(In reply to re: Part 1 with no reset
There is no indication in part (i) that either odometer has any digit limit. So I assumed none.
Part (ii) required it, but I pressed the reset button rather than consider a rollover as you did.
I don't think either method is wrong. The problem is more open than expected.
Posted by Jer
on 2013-03-27 08:03:16