Unlocking the secret in product codes
Arnold's Challenges

Here are five challenges that build on the ideas you’ve been working with. You might like to do one a day... The first one of each set should be fairly easy, but they get harder. You can type in your answer. What do you get out of this? Just the warm feeling you get when you know you've solved one of Arnold's challenges, and the satisfaction of knowing that you've mastered a deep idea from computer science.

Enjoy the challenges!

Challenges

Challenge #1

If a product scans with the 13-digit code 9 414942 119252, is it likely to have been scanned correctly? (Type in yes or no).

Challenge #2

What is the check digit that’s missing from this 12-digit product code? 7 19821 37345 _

Challenge #3

What is the check digit that’s missing from this 13-digit product code? 9 300652 80460_

Challenge #4

The first digit on this product is smudged - can you work out what it is?

A thirteen digit product code with the first digit smudged. The rest of the digits are 400547010059.

Challenge #5

The second digit on this product is smudged - can you work out what it is?

A thirteen digit product code with the second digit smudged. The digits are 9, followed by the smudged digit, followed by 00657233860.
Correct! Great work!
Sorry, that is incorrect.
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