Kode #191: hints & solution
Here's the clue board for Kode #191. 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.
- 13614▲1●1
- 22694▲0●1
- 30514▲0●2
- 47620▲0●0
- 50219▲0●2
Spoiler-free hints
- All four digits are odd.
- The four digits add up to 18.
- 2 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 4 (7 6 2 0) has no marks at all, so 7, 6, 2, and 0 are not in the code.
- Row 5 (0 2 1 9) has 2 marks still unexplained, and only 2 digits are left undecided: 1 and 9. So both are in the code.
- Row 2 (2 6 9 4) has one mark, already accounted for by 9. That rules out 4.
- Row 1 (3 6 1 4) has one mark still unexplained, and only one digit is left undecided: 3. So it is in the code.
- Row 3 (0 5 1 4) has one mark still unexplained, and only one digit is left undecided: 5. So it is in the code.
- That makes all four digits of the code: 1, 3, 5, and 9. Every other digit is out, which also rules out 8.
- Row 1 (3 6 1 4) has one digit in the right spot. Since row 3 rules out the 1 in position 3, it has to be the 3 in position 1.
- The 9 has only one spot left: position 2 (row 2 rules out position 3, row 5 rules out position 4, and position 1 is already 3).
- The 1 has only one spot left: position 4 (row 3 rules out position 3, position 1 is already 3, and position 2 is already 9).
- That leaves the 5 for position 3.
That cracks it: the code is 3951.