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Sat 23 Feb, 2008 06:11 am
Every labourer working on the Great Pyramid of Giza wore an identification tag. This tag bore a number such as:
8006358Y
This number is made up of seven digits and a letter at the end. This letter is derived from a check digit calculated from the seven digits using the modulus eleven method. For any given identification tag, the check digit can be validated using the following steps:
* Multiply each digit in the identification number by its weight.
* Add together the above products.
* Divide the resulting sum by 11.
* Subtract the remainder from 11 to give the check digit.
* Check the check digit against the table to obtain the alphabet.
The weights and the digit-to-letter matching table are given as follows:
2 7 6 5 4 3 2
1 2 3 4 5 6 7 8 9 10 11
P Q R S T U V W X Y Z
Given the information above, help to recover the last three digits of the partial identification number below:
8233***Q
There is not a unique solution. If the last three digits are xyz, then:
(4x+3y+2z) mod 11 = 1