Kode #101: hints & solution
Here's the clue board for Kode #101. 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.
- 11578▲1●1
- 20673▲0●2
- 39108▲0●1
- 43097▲0●2
- 50321▲0●0
Spoiler-free hints
- Exactly one of the four digits is even.
- The four digits add up to 27.
- 4 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 (0 3 2 1) has no marks at all, so 0, 3, 2, and 1 are not in the code.
- Row 2 (0 6 7 3) has 2 marks still unexplained, and only 2 digits are left undecided: 6 and 7. So both are in the code.
- Row 4 (3 0 9 7) has one mark still unexplained, and only one digit is left undecided: 9. So it is in the code.
- Row 3 (9 1 0 8) has one mark, already accounted for by 9. That rules out 8.
- Row 1 (1 5 7 8) 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: 5, 6, 7, and 9. Every other digit is out, which also rules out 4.
- Row 1 (1 5 7 8) has one digit in the right spot. Since row 2 rules out the 7 in position 3, it has to be the 5 in position 2.
- The 7 has only one spot left: position 1 (row 2 rules out position 3, row 4 rules out position 4, and position 2 is already 5).
- The 9 has only one spot left: position 4 (row 4 rules out position 3, position 1 is already 7, and position 2 is already 5).
- That leaves the 6 for position 3.
That cracks it: the code is 7569.