Split #15 — the solution

The three rounds from October 14, 2026: twelve numbers each, split into four groups of three that add to the target — the one way each round allows, with its decoys and where the reasoning starts.

Round 1 — target 26

The numbers: 1, 4, 11, 20, 13, 2, 8, 10, 9, 3, 6, 17. 3 decoys.

The groups: 1 + 8 + 17, 4 + 20 + 2, 11 + 9 + 6, 13 + 10 + 3.

The decoys — triples that add to 26 but are not in the answer: 4 + 13 + 9; 11 + 13 + 2; 3 + 6 + 17.

Where to start: 1, 20, 8 and 10 sit in only one on-target triple, so their groups are certain — start there.

Round 2 — target 32

The numbers: 4, 8, 17, 2, 9, 12, 20, 5, 19, 13, 3, 16. 4 decoys.

The groups: 4 + 12 + 16, 8 + 5 + 19, 17 + 2 + 13, 9 + 20 + 3.

The decoys — triples that add to 32 but are not in the answer: 4 + 8 + 20; 4 + 9 + 19; 17 + 12 + 3; 13 + 3 + 16.

Where to start: 2 and 5 sit in only one on-target triple, so their groups are certain — start there.

Round 3 — target 36

The numbers: 3, 17, 19, 7, 12, 13, 9, 10, 18, 5, 11, 20. 6 decoys.

The groups: 3 + 13 + 20, 17 + 9 + 10, 19 + 12 + 5, 7 + 18 + 11.

The decoys — triples that add to 36 but are not in the answer: 17 + 7 + 12; 19 + 7 + 10; 7 + 9 + 20; 12 + 13 + 11; 13 + 18 + 5; 5 + 11 + 20.

Where to start: 3 sits in only one on-target triple, so its group is certain — start there.

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About Split

Split is Noggin’s number puzzle, on the second shelf: twelve numbers into four groups of three, three rounds a day, outside the daily line-up. How to play Split, or play today’s.