Answer to Question #308264 in Financial Math for Dian

Question

Verify if the ISBN 978-0-760-73261-6 is valid?

Answer 1

Solution

Given that ISBN 978-0-760-73261-6

The given ISBN is 13 digit ISBN number

We assign the position of each number from right to left

For

9 the position is 13

7 the position is 12

8 the position is 11

0 the position is 10

7 the position is 9

6 the position is 8

0 the position is 7

7 the position is 6

3 the position is 5

2 the position is 4

6 the position is 3

1 the position is 2

6 the position is 0

Now we the Odd number positions by 1 and Even number positions by 3.

$9 × (1) + 7 ×(3)+8 ×(1)+0 ×(3)+7 ×(1)+6 ×(3)+0 ×(1)+7 ×(3)+3 ×(1)+2 ×(3)+6 ×(1)+1 ×(3)+6 ×(1)\\ =108$

Now we divide this sum by $10$ and see that the remainder is $8≠0$

$\frac{108}{10}=10+\frac{8}{10}$

since the remainder is not zero, therefore, the given ISBN number is not a valid ISBN number.