This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: 4. Credit Card # : same as number 3, sum(mod 10) = 0 and sum without ? = 69 Thus, 1 is correct, because it makes the sum = 70(mod 10) = 0 5. UPC : Left to Right, Triple Odd and just bring down the Even, sum(mod 10) = 0 Thus, 5 is correct answer, because tripling 5 lowers the sum 6, making sum= 100(mod 10)= 0 6. ISBN : Left to Right, Multiply each number by its position, sum(mod 11) = check digit Thus, sum = 112(mod 11) = 2 7. ISBN : sum(mod 11) = 10 and sum = 204 ≠ 10 when you take (mod 11) of it (b) because it makes the sum = 186(mod 11) = 10...
View
Full Document
 Winter '08
 Kehler
 Addition, Credit card, Prime number, MasterCard, Visa Inc., Vigenere square

Click to edit the document details