Kode #82: hints & solution
Here's the clue board for Kode #82. 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.
- 10918▲1●1
- 20412▲0●1
- 32705▲0●2
- 48156▲1●1
- 52478▲0●0
Spoiler-free hints
- 2 of the four digits are even.
- The four digits add up to 20.
- 3 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 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 5 (2 4 7 8) has no marks at all, so 2, 4, 7, and 8 are not in the code.
- Row 3 (2 7 0 5) has 2 marks still unexplained, and only 2 digits are left undecided: 0 and 5. So both are in the code.
- Row 2 (0 4 1 2) has one mark, already accounted for by 0. That rules out 1.
- Row 1 (0 9 1 8) has one mark still unexplained, and only one digit is left undecided: 9. So it is in the code.
- Row 4 (8 1 5 6) has one mark still unexplained, and only one digit is left undecided: 6. So it is in the code.
- That makes all four digits of the code: 0, 5, 6, and 9. Every other digit is out, which also rules out 3.
- Row 1 (0 9 1 8) has one digit in the right spot. Since row 2 rules out the 0 in position 1, it has to be the 9 in position 2.
- The 0 has only one spot left: position 4 (row 2 rules out position 1, row 3 rules out position 3, and position 2 is already 9).
- Row 4 (8 1 5 6) has one digit in the right spot. Since position 4 is already 0, it has to be the 5 in position 3.
- That leaves the 6 for position 1.
That cracks it: the code is 6950.