Kode #36: hints & solution
Here's the clue board for Kode #36. 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.
- 12671▲1●1
- 29071▲0●1
- 39457▲0●2
- 43790▲0●0
- 51604▲0●2
Spoiler-free hints
- 2 of the four digits are even.
- The four digits add up to 12.
- 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 10 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.
- Row 4 (3 7 9 0) has no marks at all, so 3, 7, 9, and 0 are not in the code.
- Row 2 (9 0 7 1) has one mark still unexplained, and only one digit is left undecided: 1. So it is in the code.
- Row 3 (9 4 5 7) has 2 marks still unexplained, and only 2 digits are left undecided: 4 and 5. So both are in the code.
- Row 5 (1 6 0 4) has 2 marks, already accounted for by 1 and 4. That rules out 6.
- Row 1 (2 6 7 1) has one mark still unexplained, and only one digit is left undecided: 2. So it is in the code.
- That makes all four digits of the code: 1, 2, 4, and 5. Every other digit is out, which also rules out 8.
- Row 1 (2 6 7 1) has one digit in the right spot. Since row 2 rules out the 1 in position 4, it has to be the 2 in position 1.
- The 4 has only one spot left: position 3 (row 3 rules out position 2, row 5 rules out position 4, and position 1 is already 2).
- The 1 has only one spot left: position 2 (row 2 rules out position 4, position 1 is already 2, and position 3 is already 4).
- That leaves the 5 for position 4.
That cracks it: the code is 2145.