Kode #52: hints & solution
Here's the clue board for Kode #52. 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.
- 11752▲1●1
- 29704▲0●2
- 38307▲0●2
- 49360▲0●0
- 51780▲1●2
Spoiler-free hints
- 2 of the four digits are even.
- The four digits add up to 20.
- 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 (9 3 6 0) has no marks at all, so 9, 3, 6, and 0 are not in the code.
- Row 2 (9 7 0 4) has 2 marks still unexplained, and only 2 digits are left undecided: 7 and 4. So both are in the code.
- Row 3 (8 3 0 7) has one mark still unexplained, and only one digit is left undecided: 8. So it is in the code.
- Row 5 (1 7 8 0) has one mark still unexplained, and only one digit is left undecided: 1. So it is in the code.
- Row 1 (1 7 5 2) has 2 marks, already accounted for by 1 and 7. That rules out 5 and 2.
- Row 1 (1 7 5 2) has one digit in the right spot. Since row 2 rules out the 7 in position 2, it has to be the 1 in position 1.
- Row 5 (1 7 8 0) has only one digit in the right spot, already accounted for by the 1 in position 1. So the 8 isn't in position 3.
- The 7 has only one spot left: position 3 (row 2 rules out position 2, row 3 rules out position 4, and position 1 is already 1).
- The 4 has only one spot left: position 2 (row 2 rules out position 4, position 1 is already 1, and position 3 is already 7).
- That leaves the 8 for position 4.
That cracks it: the code is 1478.