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Kode #115: hints & solution

Here's the clue board for Kode #115. 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.

  • 17183▲1●1
  • 27456▲0●2
  • 30872▲0●2
  • 45369▲1●1
  • 50245▲0●0

Spoiler-free hints

  • 2 of the four digits are even.
  • The four digits add up to 30.
  • 4 of the digits are 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 (0 2 4 5) has no marks at all, so 0, 2, 4, and 5 are not in the code.
  2. Row 2 (7 4 5 6) has 2 marks still unexplained, and only 2 digits are left undecided: 7 and 6. So both are in the code.
  3. Row 3 (0 8 7 2) has one mark still unexplained, and only one digit is left undecided: 8. So it is in the code.
  4. Row 1 (7 1 8 3) has 2 marks, already accounted for by 7 and 8. That rules out 1 and 3.
  5. Row 4 (5 3 6 9) has one mark still unexplained, and only one digit is left undecided: 9. So it is in the code.
  6. Row 1 (7 1 8 3) has one digit in the right spot. Since row 2 rules out the 7 in position 1, it has to be the 8 in position 3.
  7. Row 4 (5 3 6 9) has one digit in the right spot. Since position 3 is already 8, it has to be the 9 in position 4.
  8. The 7 has only one spot left: position 2 (row 2 rules out position 1, position 3 is already 8, and position 4 is already 9).
  9. That leaves the 6 for position 1.

That cracks it: the code is 6789.

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