Kode #177: hints & solution
Here's the clue board for Kode #177. 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.
- 14197▲1●1
- 29157▲0●2
- 32765▲0●2
- 46703▲0●0
- 52361▲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 (6 7 0 3) has no marks at all, so 6, 7, 0, and 3 are not in the code.
- Row 3 (2 7 6 5) has 2 marks still unexplained, and only 2 digits are left undecided: 2 and 5. So both are in the code.
- Row 5 (2 3 6 1) has one mark still unexplained, and only one digit is left undecided: 1. So it is in the code.
- Row 2 (9 1 5 7) has 2 marks, already accounted for by 1 and 5. That rules out 9.
- Row 1 (4 1 9 7) has one mark still unexplained, and only one digit is left undecided: 4. 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 (4 1 9 7) has one digit in the right spot. Since row 2 rules out the 1 in position 2, it has to be the 4 in position 1.
- The 1 has only one spot left: position 3 (row 2 rules out position 2, row 5 rules out position 4, and position 1 is already 4).
- The 5 has only one spot left: position 2 (row 3 rules out position 4, position 1 is already 4, and position 3 is already 1).
- That leaves the 2 for position 4.
That cracks it: the code is 4512.