Kode #2: hints & solution
Here's the clue board for Kode #2. 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.
- 19104▲1●1
- 28176▲0●2
- 32419▲1●1
- 41657▲0●1
- 54695▲0●0
Spoiler-free hints
- 3 of the four digits are even.
- The four digits add up to 11.
- 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 5 (4 6 9 5) has no marks at all, so 4, 6, 9, and 5 are not in the code.
- Row 1 (9 1 0 4) has 2 marks still unexplained, and only 2 digits are left undecided: 1 and 0. So both are in the code.
- Row 3 (2 4 1 9) has one mark still unexplained, and only one digit is left undecided: 2. So it is in the code.
- Row 4 (1 6 5 7) has one mark, already accounted for by 1. That rules out 7.
- Row 2 (8 1 7 6) has one mark still unexplained, and only one digit is left undecided: 8. So it is in the code.
- That makes all four digits of the code: 0, 1, 2, and 8. Every other digit is out, which also rules out 3.
- Row 1 (9 1 0 4) has one digit in the right spot. Since row 2 rules out the 1 in position 2, it has to be the 0 in position 3.
- Row 3 (2 4 1 9) has one digit in the right spot. Since position 3 is already 0, it has to be the 2 in position 1.
- The 1 has only one spot left: position 4 (row 2 rules out position 2, position 1 is already 2, and position 3 is already 0).
- That leaves the 8 for position 2.
That cracks it: the code is 2801.