Can you crack the code and solve the number lock puzzle with minimum clues? Given, five clues with hints on possible code and correctness information.

## Solve the Number Lock Puzzle with Minimum Clues

Find the 3 digit code from the five clues to unlock the number lock:

**Clue 1: Code 7 2 5 :** One digit right and but wrongly placed.

**Clue 2: Code 3 1 7 :** Two digits are right both in wrong place.

**Clue 3: Code 7 9 3 :** One digit correct and in place.

**Clue 4: Code 8 4 9 :** Nothing is correct.

**Clue 5: Code 8 9 1 :** One digit correct but in wrong place.

### Solution to the 5 clue 3 digit number lock puzzle with 725 in clues: Use least number of clues

#### Step 1: Identify the first pair of incorrect digits

From Clue 1 and 3, digit 7 is wrong due to **correctness and positional conflict.**

**Clue 1: Code 7 2 5 :** One digit right and but wrongly placed.

**Clue 3: Code 7 9 3 :** One digit correct and in place.

- Digit 7 cannot be correct in both and in wrong position in one and in correct place in the other as it appears in the same position in both.
**Digit 7 in incorrect.**

In the same way, from Clue 3 and Clue 5, digit 9 is incorrect.

**Clue 3: Code 7 9 3 :** One digit correct and in place.

**Clue 5: Code 8 9 1 :** One digit correct but in wrong place.

- Digit 9 cannot be correct in both and in wrong position in one and in place in the other, as it appears in the same position in both.
**Digit 9 is incorrect.**

#### Step 2: Identify the first correct digit and its place

From Clue 3, digit 3 is correct and in 3rd place.

**Clue 3: Code 7 9 3 :** One digit correct and in place.

- As both 7 and 9 are incorrect,
**digit 3 is the single correct digit**and is**in 3rd position**in the correct code.

#### Step 3: Identify the second correct digit and its place

From Clue 2, the second correct digit is 1.

**Clue 2: Code 3 1 7 :** Two digits are right both in wrong place.

- Digit 7 is incorrect and digit 3 correct.
**Digit 1 must be the second correct digit.** *As 3rd place is taken up by digit 3 and 2nd place wrong for*,**digit 1****its correct position is 1st.**

#### Step 4: Identify the third correct digit and crack the code

From Clue 1, digit 5 is the third correct digit.

**Clue 1: Code 7 2 5 :** One digit right and but wrongly placed.

- With digit 7 wrong, either of digits 2 or 5 is right.
*Both 1st and 3rd positions are taken up and 2nd position is wrong for***digit 2**.**It has no place to go**and**must be incorrect**.**Digit 5 is the third correct digit and in 2nd position.**

**Code** to open the number lock is **1 5 3.**

*Verify the code against the 5 clues.*

**Note:** *Only 4 clues are used.* Clue 4 remains unused. This is the hallmark of *efficient solution using least number of clues by expert logical reasoning with no loophole.*

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