Split #18 — the solution

The three rounds from October 17, 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 30

The numbers: 1, 5, 18, 7, 20, 15, 13, 11, 6, 19, 2, 3. 2 decoys.

The groups: 1 + 18 + 11, 5 + 6 + 19, 7 + 20 + 3, 15 + 13 + 2.

The decoys — triples that add to 30 but are not in the answer: 5 + 18 + 7; 13 + 11 + 6.

Where to start: 1, 20, 15, 19, 2 and 3 sit in only one on-target triple, so their groups are certain — start there.

Round 2 — target 35

The numbers: 5, 20, 12, 10, 19, 6, 2, 15, 7, 13, 14, 17. 5 decoys.

The groups: 5 + 20 + 10, 12 + 6 + 17, 19 + 2 + 14, 15 + 7 + 13.

The decoys — triples that add to 35 but are not in the answer: 5 + 13 + 17; 20 + 2 + 13; 12 + 10 + 13; 10 + 19 + 6; 6 + 15 + 14.

Where to start: 7 sits in only one on-target triple, so its group is certain — start there.

Round 3 — target 32

The numbers: 7, 10, 8, 18, 19, 11, 9, 2, 13, 16, 12, 3. 6 decoys.

The groups: 7 + 9 + 16, 10 + 19 + 3, 8 + 11 + 13, 18 + 2 + 12.

The decoys — triples that add to 32 but are not in the answer: 7 + 13 + 12; 10 + 9 + 13; 18 + 11 + 3; 19 + 11 + 2; 11 + 9 + 12; 13 + 16 + 3.

Where to start: 8 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.