Kode #70: hints & solution
Here's the clue board for Kode #70. 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.
- 18256▲1●1
- 27406▲0●2
- 36570▲1●1
- 49168▲0●2
- 50781▲0●0
Spoiler-free hints
- 2 of the four digits are even.
- The four digits add up to 24.
- 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 (0 7 8 1) has no marks at all, so 0, 7, 8, and 1 are not in the code.
- Row 2 (7 4 0 6) has 2 marks still unexplained, and only 2 digits are left undecided: 4 and 6. So both are in the code.
- Row 3 (6 5 7 0) has one mark still unexplained, and only one digit is left undecided: 5. So it is in the code.
- Row 1 (8 2 5 6) has 2 marks, already accounted for by 5 and 6. That rules out 2.
- Row 4 (9 1 6 8) has one mark still unexplained, and only one digit is left undecided: 9. So it is in the code.
- That makes all four digits of the code: 4, 5, 6, and 9. Every other digit is out, which also rules out 3.
- Row 1 (8 2 5 6) has one digit in the right spot. Since row 2 rules out the 6 in position 4, it has to be the 5 in position 3.
- Row 3 (6 5 7 0) has one digit in the right spot. Since the 5 is already in position 3, it has to be the 6 in position 1.
- The 4 has only one spot left: position 4 (row 2 rules out position 2, position 1 is already 6, and position 3 is already 5).
- That leaves the 9 for position 2.
That cracks it: the code is 6954.