Number lock puzzle 9285: Can you crack the 4 digit number lock code from the five clues? Each 4 digit clue hints on correct digits and placements.

### The 4 digit number lock puzzle 9285

Find the 4 digit code from the five clues to unlock the number lock:

**Clue 1: Code 9 2 8 5 :**One digit right but in wrong position.**Clue 2: Code 1 9 3 7 :**Two digits are correct but wrongly placed.**Clue 3: Code 5 2 0 1 :**One digit is correct and well placed.**Clue 4: Code 6 5 0 7 :**Nothing is correct.**Clue 5: Code 8 5 2 4 :**Two digits right but wrongly placed.

### Solution to the 4 digit number lock puzzle 9285

**First objective** to solve a 4 digit number lock riddle with 5 clues must be,

- To eliminate as many as digits as possible from the set of possible 10 digits.

**Second objective** must be to,

- Identify the correct digits from the short-listed possible digits.

And the **third objective** is to,

- Identify the placement of the correct digits.

#### Step 1: Clue 4 eliminates maximum number of possible digits

**Clue 4: Code 6 5 0 7 :** Nothing is correct.

Digits 6, 5, 0 and 7 are eliminated at one go.

- Possible correct digits
**1, 2, 3, 4, 8 and 9.**

#### Step 2: Identify correct or incorrect digits: Breakthrough in the number lock riddle

*No other clue alone identifies a correct or incorrect digit.*

- More than one clue must be used together.

This is where conflict of correctness and position help. **Such a conflict for digit 2 arises in Clue 1 and Clue 3.**

**Clue 1: Code 9 2 8 5 :** One digit right but in wrong position.

**Clue 3: Code 5 2 0 1 :** One digit is correct and well placed.

*Digit 2 appears in both clues in 2nd position, but in Clue 1, correct digit is wrongly placed and in Clue 3, it is well placed.*

**Digit 2 must be a wrong digit.**It cannot be a correct digit.

- Possible correct digits are
**1, 3, 4, 8 or 9.**

*This is the most important breakthrough in the puzzle.*

#### Step 3: Identify more correct and incorrect digits

**Clue 5 stands out.** With digit 2 identified as incorrect, only two possible correct digits 4 and 8 are used in the clue.

**Clue 5: Code 8 5 2 4 :** Two digits right but wrongly placed.

**Digits 4 and 8 are confirmed correct.**- Other possible correct digits are 1, 3 and 9.

Now **Clue 3 gives us one more correct digit as well as its position.**

**Clue 3: Code 5 2 0 1 :** One digit is correct and well placed.

With digit 2 identified as incorrect, only digit 1 is a possible correct digit left.

**Digit 1 must be the correct digit**and**its position is**also certain as the**4th**.- Possible correct digits are digits 3 and 9.

With digit 2 identified as incorrect and digit 8 correct, Clue 1 gives us the **final breakthrough on correctness of digits **(but not on positions).

**Clue 1: Code 9 2 8 5 :** One digit right but in wrong position.

**Digit 9 must be the incorrect digit**when digit 8 is correct.- The only possible candidate left
**3 is the fourth correct digit.** - The
**correct digits are 4, 8, 1 and 3.**

#### Step 4: Placement analysis of digit 8 from Clue 1 and Clue 5

**Clue 1: Code 9 2 8 5 :** One digit right but in wrong position.

**Clue 5: Code 8 5 2 4 :** Two digits right but wrongly placed.

*Digit 8 appears in Clue 1 in 3rd position and in Clue 5 in 1st position, and both are wrong.*

**Position of digit 8 must be the 2nd**(4th is already occupied by digit 1).- Digits 3 and 4 are to be correctly placed in the 1st and 3rd position left.

#### Step 5: Final solution of the number lock riddle by placement analysis

**Digit 3 appears only in Clue 2.** This will give us the solution.

**Clue 2: Code 1 9 3 7 :** Two digits are correct but wrongly placed.

- 3rd position for digit 3 is wrong.
**The only position left for it is the 1st**(as 2nd and 4th already fixed). **Position of digit 4 is the 3rd**, the only position still not fixed.

The **number lock code to open the lock** is **3 8 4 1**.

Verify the correctness of the code by tallying the code with each of the five clues.

To enjoy solving many more number lock puzzles, click **here.**

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