Kode #96: hints & solution
Here's the clue board for Kode #96. 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.
- 14951▲1●1
- 27931▲1●1
- 38341▲1●1
- 46740▲1●0
- 57563▲0●0
Spoiler-free hints
- 2 of the four digits are even.
- The four digits add up to 18.
- 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 5 (7 5 6 3) has no marks at all, so 7, 5, 6, and 3 are not in the code.
- Row 2 (7 9 3 1) has 2 marks still unexplained, and only 2 digits are left undecided: 9 and 1. So both are in the code.
- Row 1 (4 9 5 1) has 2 marks, already accounted for by 9 and 1. That rules out 4.
- Row 3 (8 3 4 1) has one mark still unexplained, and only one digit is left undecided: 8. So it is in the code.
- Row 4 (6 7 4 0) has one mark still unexplained, and only one digit is left undecided: 0. So it is in the code.
- That makes all four digits of the code: 0, 1, 8, and 9. Every other digit is out, which also rules out 2.
- Row 4 (6 7 4 0) has one digit in the right spot, and the 0 in position 4 is its only digit in the code, so it's locked in.
- Row 1 (4 9 5 1) has one digit in the right spot. Since position 4 is already 0, it has to be the 9 in position 2.
- Row 3 (8 3 4 1) has one digit in the right spot. Since position 4 is already 0, it has to be the 8 in position 1.
- That leaves the 1 for position 3.
That cracks it: the code is 8910.