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Kode #199: hints & solution

Here's the clue board for Kode #199. Start with the spoiler-free hints. If you're still stuck, the full step-by-step solution is below, hidden until you open it.

Play Kode #199

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.

  • 17036▲1●1
  • 21076▲0●2
  • 36102▲1●1
  • 44510▲0●2
  • 55902▲0●0

Spoiler-free hints

  • 2 of the four digits are even.
  • The four digits add up to 14.
  • 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 11 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 (5 9 0 2) has no marks at all, so 5, 9, 0, and 2 are not in the code.
  2. Row 3 (6 1 0 2) has 2 marks still unexplained, and only 2 digits are left undecided: 6 and 1. So both are in the code.
  3. Row 2 (1 0 7 6) has 2 marks, already accounted for by 1 and 6. That rules out 7.
  4. Row 1 (7 0 3 6) has one mark still unexplained, and only one digit is left undecided: 3. So it is in the code.
  5. Row 4 (4 5 1 0) has one mark still unexplained, and only one digit is left undecided: 4. So it is in the code.
  6. That makes all four digits of the code: 1, 3, 4, and 6. Every other digit is out, which also rules out 8.
  7. Row 1 (7 0 3 6) has one digit in the right spot. Since row 2 rules out the 6 in position 4, it has to be the 3 in position 3.
  8. Position 1 can only be 6 (row 2 rules out 1 and row 4 rules out 4).
  9. Row 3 (6 1 0 2) has only one digit in the right spot, already accounted for by the 6 in position 1. So the 1 isn't in position 2.
  10. The 1 has only one spot left: position 4 (row 3 rules out position 2, position 1 is already 6, and position 3 is already 3).
  11. That leaves the 4 for position 2.

That cracks it: the code is 6431.

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