Can you find the code to open the 3 digit number lock from the five clues each with a code and placement description? Go for the most efficient solution.
3 Digit Number lock puzzle with five clues including 682
Following are five clues each with a three-digit code for a number lock. Find the code to open the lock from the clues.
Clue 1: Code 682: One digit is right and is in its place.
Clue 2: Code 614: One digit is right and is in the wrong place.
Clue 3: Code 206: Two digits are right, but both are in the wrong place.
Clue 4: Code 738: All digits are wrong.
Clue 5: Code 380: One digit right and is in the wrong place.
From the clues, find the three-digit code that will open the number lock.
Time to solve: 10 minutes.
Solution to the 3 digit number lock puzzle with five clues including 682
Identify the promising pair of clues 1 and 2. In both, digit 6 appears in 1st position with conflicting placement description.
Clue 1: Code 682: One digit is right and is in its place.
Clue 2: Code 614: One digit is right and is in the wrong place.
- If digit 6 is the right digit, by Clue 1, its right position is the first, but by the second Clue, the right digit is wrongly placed. The conflict identifies the digit 6 as wrong.
Look for a clue with digit 6, the already identified incorrect digit. It will help in identifying right digits. Such a clue is Clue 3.
Clue 3: Code 206: Two digits are right, but both are in the wrong place.
- As digit 6 is wrong, both digits 2 and 0 are two right digits.
Find the correct placements of the two right digits
Return to Clue 1 with single right digit 2.
Clue 1: Code 682: One digit is right and is in its place.
- Digit 2 already identified as a correct digit. Position of digit 2 in the correct code is rightmost.
Analyze Clue 3 again as it includes both both correct digits 2 and 0.
Clue 3: Code 206: Two digits are right, but both are in the wrong place.
- Digit 2 occupies rightmost position and middle position for the other right digit 0 is wrong. So, right position for digit 0 must be the leftmost.
- The code to open the lock is of the form 0 ? 2.
Identify the third right digit for solution of the number lock riddle
Observe in Clue 2, one of the two possible right digits 1 and 4 (as digit 6 is wrong) occupies the only available middle position.
Clue 2: Code 614: One digit is right and is in the wrong place.
- Digit 1 occupies the only available middle position and its position is wrong. Digit 1 doesn't have any place in the code.
- Digit 1 is the second wrong digit in 614.
- Digit 4 is the 3rd right digit and its position is in the middle of the code.
The code to open the number lock is 0 4 2.
The Clue 4 and Clue 5 remain unused in this solution. This confirms it as the most efficient solution.
Comment
This is a reasoning puzzle with each clue a condition to be processed together with other clues gradually moving towards the solution. Challenge is how quick you can reach the solution.
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