A clock breaks into three pieces along two straight cracks, and each piece's numbers add up to the same total.

A wall clock falls and breaks into three pieces along two straight cracks. No number is split, and the three totals match. The story asks which numbers are on each piece. You pick one of four answers. Then you step through the answer and the breakdown.

Why quant interviews test this

This tests starting from what can't change, then using the geometry to cut the search down. The written solution is at /brain-teasers/broken-clock/solution.

The The Broken Clock guide covers how scoring works, the strategy that wins, a worked example and the mistakes most players make.

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