← All puzzles

Kode #64: hints & solution

Here's the clue board for Kode #64. Start with the spoiler-free hints. If you're still stuck, the full step-by-step solution is below, hidden until you open it.

The clue board

Each row is a guess that's already been graded. ▲ means a right digit in the right spot; ● means a right digit in the wrong spot.

  • 11083▲1●1
  • 27285▲0●2
  • 33017▲0●2
  • 44720▲0●2
  • 57346▲0●0

Spoiler-free hints

  • 2 of the four digits are even.
  • The four digits add up to 8.
  • Just one digit is 5 or higher.

Try the hints first. The solution below walks through every deduction.

Step-by-step solution

Every Kode can be cracked by pure deduction, with no guessing. This board falls in 9 logical steps. Open the solution to follow them one at a time.

Show the solution · reveals the code

When a row "rules out" a position, it shows that digit there but its ▲ marks are already used up (or it has none), so the digit can't sit there.

  1. Row 5 (7 3 4 6) has no marks at all, so 7, 3, 4, and 6 are not in the code.
  2. Row 3 (3 0 1 7) has 2 marks still unexplained, and only 2 digits are left undecided: 0 and 1. So both are in the code.
  3. Row 1 (1 0 8 3) has 2 marks, already accounted for by 1 and 0. That rules out 8.
  4. Row 2 (7 2 8 5) has 2 marks still unexplained, and only 2 digits are left undecided: 2 and 5. So both are in the code.
  5. That makes all four digits of the code: 0, 1, 2, and 5. Every other digit is out, which also rules out 9.
  6. Row 1 (1 0 8 3) has one digit in the right spot. Since row 3 rules out the 0 in position 2, it has to be the 1 in position 1.
  7. The 0 has only one spot left: position 3 (row 3 rules out position 2, row 4 rules out position 4, and position 1 is already 1).
  8. The 2 has only one spot left: position 4 (row 2 rules out position 2, position 1 is already 1, and position 3 is already 0).
  9. That leaves the 5 for position 2.

That cracks it: the code is 1502.

Play today's Kode