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Kode #170: hints & solution

Here's the clue board for Kode #170. 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.

  • 17419▲1●1
  • 27256▲0●2
  • 30937▲0●2
  • 45192▲1●1
  • 55890▲0●0

Spoiler-free hints

  • Exactly one of the four digits is even.
  • The four digits add up to 13.
  • 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 (5 8 9 0) has no marks at all, so 5, 8, 9, and 0 are not in the code.
  2. Row 3 (0 9 3 7) has 2 marks still unexplained, and only 2 digits are left undecided: 3 and 7. So both are in the code.
  3. Row 4 (5 1 9 2) has 2 marks still unexplained, and only 2 digits are left undecided: 1 and 2. So both are in the code.
  4. Row 1 (7 4 1 9) has 2 marks, already accounted for by 7 and 1. That rules out 4.
  5. Row 2 (7 2 5 6) has 2 marks, already accounted for by 7 and 2. That rules out 6.
  6. Row 1 (7 4 1 9) has one digit in the right spot. Since row 2 rules out the 7 in position 1, it has to be the 1 in position 3.
  7. Row 4 (5 1 9 2) has one digit in the right spot. Since the 1 is already in position 3, it has to be the 2 in position 4.
  8. The 7 has only one spot left: position 2 (row 2 rules out position 1, position 3 is already 1, and position 4 is already 2).
  9. That leaves the 3 for position 1.

That cracks it: the code is 3712.

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