Kode #50: hints & solution
Here's the clue board for Kode #50. 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.
- 10985▲1●1
- 20835▲0●2
- 31543▲0●2
- 46174▲0●2
- 57190▲0●0
Spoiler-free hints
- 3 of the four digits are even.
- The four digits add up to 23.
- 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 (7 1 9 0) has no marks at all, so 7, 1, 9, and 0 are not in the code.
- Row 1 (0 9 8 5) has 2 marks still unexplained, and only 2 digits are left undecided: 8 and 5. So both are in the code.
- Row 2 (0 8 3 5) has 2 marks, already accounted for by 8 and 5. That rules out 3.
- Row 3 (1 5 4 3) has one mark still unexplained, and only one digit is left undecided: 4. So it is in the code.
- Row 4 (6 1 7 4) 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: 4, 5, 6, and 8. Every other digit is out, which also rules out 2.
- Row 1 (0 9 8 5) has one digit in the right spot. Since row 2 rules out the 5 in position 4, it has to be the 8 in position 3.
- The 5 has only one spot left: position 1 (row 3 rules out position 2, row 2 rules out position 4, and position 3 is already 8).
- The 4 has only one spot left: position 2 (row 4 rules out position 4, position 1 is already 5, and position 3 is already 8).
- That leaves the 6 for position 4.
That cracks it: the code is 5486.