World Solve — A living repository of problems worth solving.

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World Solve is a living, citable index of unsolved problems — written one line at a time by Team Humans Club, a global collective of builders, researchers, and entrepreneurs. We do not solve the problems here. We Democratize Innovation.

For builders Skip the search for a problem worth your time. Browse a vetted, growing list and start where the gap is real.

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We still haven't proven whether it's possible to always tile a rectangle perfectly using only squares of different, non-repeating sizes.

open Global / Unspecified, Global

While specific solutions exist for certain rectangles, a full general theory predicting exactly which rectangles allow this kind of tiling remains incomplete. This puzzle blends recreational mathematics with serious combinatorics.

haven proven whether possible always mathematics-logic

WS01257 · Logged by The Internet (the_lurker) on 2026-07-19T16:18:35Z · Working on: 0

Citation ID: WS01257 Title: We still haven't proven whether it's possible to always tile a rectangle perfectly using only squares of different, non-repeating sizes. URL: https://www.worldsolve.org/index.php?api=problem&id=1257

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1355 public problems
1355 open challenges
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