Albert remarked that even when it is turned upside down, the number plate of his car still made sense.

He observed that this would however increase the registration number on it by 8505.

Given, all of the four digits in the number is different, find out what was his car license number?

As fwaff pointed out, the digits available are restricted only by the font used, therefore valid solutions, besides 1096 (+ 8505 = 9601) would include 1056 (+ 8505 = 5961) and 1296 (+ 8505 = 9801).
They would also include 1086, 1095 and 1295 -- even though these three numbers, when flipped, do not have distinct digits we were not limited to that restriction as the problem only restricts it of the original number.
We also were not restricted against the use of leading zeroes (which can be found on some license plates), thus
0296, 0516, 0521, 0561, 0581, 0586, 0591, 0596, 0615, 0621, 0651, 0681, 0685 and 0691 are also valid solutions.
[Note: 0681 and 0691 are valid even if digits 2 and 5 are excluded due to font restrictions, and 0681 (+ 8505 = 9186) is still valid even if we add the restriction that the digits are distinct when flipped].

Unfortunately, we have increased this list of numbers to 20 numbers and would be unable to absolutely determine Albert's registration number by doing so without being given further clues.

 

Posted by Dej Mar on 2007-11-29 21:31:00