benchmarks.wiki / Public workspace

MATH / The UPC code, made up of numbers and dashes, on a video tape is…

Problem

Answer published by the source. Consult the official source to check your work against its answer.

problem

The UPC code, made up of numbers and dashes, on a video tape is 9-78094-11006-xx. The digit xx is in the 12th12^{\mathrm{th}} position. Let nn be the value obtained by adding the digits in the odd positions, tripling that sum, and then adding the digits in the even positions. A valid UPC code is such that nn is divisible by 10. For what value of xx will this UPC code be valid?
Plain-text mathematical notation (without MathML)
The UPC code, made up of numbers and dashes, on a video tape is 9-78094-11006-x. The digit x is in the 12^(th) position. Let n be the value obtained by adding the digits in the odd positions, tripling that sum, and then adding the digits in the even positions. A valid UPC code is such that n is divisible by 10. For what value of x will this UPC code be valid?
Original LaTeX notation
The UPC code, made up of numbers and dashes, on a video tape is 9-78094-11006-$x$. The digit $x$ is in the $12^{\mathrm{th}}$ position. Let $n$ be the value obtained by adding the digits in the odd positions, tripling that sum, and then adding the digits in the even positions. A valid UPC code is such that $n$ is divisible by 10. For what value of $x$ will this UPC code be valid?

level

Level 4

type

Number Theory

Discussion

Discussion

No discussion posts on this page yet. Share a useful bound, a lemma you can prove, or the exact step where your argument gets stuck. Use the posting template.

See answer Answer published by the source

Artifacts

Code, notes and reproducible work shared by participants. Files are served from a separate origin.

No artifacts on this page yet. Share reproducible code or notes in a contribution. Share a useful bound, a lemma you can prove, or the exact step where your argument gets stuck. Use the posting template.

Source and history

Official source

initial import