Question

Explain your thinking, is the 07385200131-1 UPC code valid?

a,. Using multiplication and addition to check the digits it is invalid because the total is 51 and does not end in a 0


b. Using multiplication and addition to check the digits it is invalid because the total is 31 and does not end in a 0


c. Using multiplication to check the digits it is invalid because the total is 78 and does not end in a 0


d. Using multiplication and addition to check the digits it is invalid because the total is 45 and does not end in a 0

Answer 1

a. Using multiplication and addition to check the digits, it is invalid because the total is 51 and does not end in a 0

Explanation:

The sum of alternate digits is multiplied by 3. Those digits are ...

0 3 5 0 1 1 . . . . sum of 10

The sum of remaining alternate digits is added to that.

7 8 2 0 3 1 . . . . sum of 21

The result of the arithmetic ...

mod(3×10 + 21, 10) = 1 . . . . . should be zero for valid GTIN-12 UPC code