Split #12 — the solution

The three rounds from October 11, 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 35

The numbers: 1, 16, 4, 10, 12, 20, 15, 2, 19, 11, 17, 13. 3 decoys.

The groups: 1 + 15 + 19, 16 + 2 + 17, 4 + 20 + 11, 10 + 12 + 13.

The decoys — triples that add to 35 but are not in the answer: 16 + 4 + 15; 4 + 12 + 19; 20 + 2 + 13.

Where to start: 1, 10, 11 and 17 sit in only one on-target triple, so their groups are certain — start there.

Round 2 — target 31

The numbers: 9, 20, 1, 16, 19, 13, 12, 17, 2, 3, 8, 4. 4 decoys.

The groups: 9 + 20 + 2, 1 + 13 + 17, 16 + 12 + 3, 19 + 8 + 4.

The decoys — triples that add to 31 but are not in the answer: 9 + 19 + 3; 20 + 3 + 8; 16 + 13 + 2; 12 + 17 + 2.

Where to start: 1 and 4 sit in only one on-target triple, so their groups are certain — start there.

Round 3 — target 30

The numbers: 15, 2, 18, 17, 5, 8, 12, 10, 4, 6, 7, 16. 7 decoys.

The groups: 15 + 5 + 10, 2 + 12 + 16, 18 + 8 + 4, 17 + 6 + 7.

The decoys — triples that add to 30 but are not in the answer: 15 + 8 + 7; 2 + 18 + 10; 18 + 5 + 7; 17 + 5 + 8; 8 + 12 + 10; 8 + 6 + 16; 10 + 4 + 16.

Where to start: No number is forced outright; 17 (2 ways), 15 (2 ways) and 12 (2 ways) have the fewest ways to reach 30, so start with those.

Previous: Split #11 (Sat, Oct 10)

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.