Crack the number lock puzzle codes including 241
You have to crack the five number lock puzzle codes with 241 in one clue. Each clue includes a 3 digit code and correctness of digit positions.
Try for the most efficient solution.
Number lock puzzle codes including 241
Following shows five clues each with a three-digit code for a number lock and descriptions of the digit positions. Find the code to open the lock from the clues.
Clue 1: Code 2 4 1 : One digit right and in right position.
Clue 2: Code 4 1 3 : All digits are wrongly placed.
Clue 3: Code 5 3 2 : Two digits right but wrongly placed.
Clue 4: Code 3 4 7 : One digit right but wrongly placed.
Clue 5: Code 7 5 1 : Two digits right but wrongly placed.
From these five clues, find the three-digit code that will open the number lock.
Finding to Number lock puzzle code with clues including 241
Identify incorrect digits
From Clue 1 and Clue 5, digit 1 is wrong.
Clue 1: Code 2 4 1 : One digit right and in right position.
Clue 5: Code 7 5 1 : Two digits right but wrongly placed.
If by Clue 1, digit 1 the right digit, 1st position must be its right position, but Clue 5 violates this placement.
- Conclusion: Digit 1 is incorrect.
From Clue 1 and Clue 4, digit 4 is wrong.
Clue 1: Code 2 4 1 : One digit right and in right position.
Clue 4: Code 3 4 7 : One digit right but wrongly placed.
Digit 4 cannot be the correct digit by Clue 1 and occupy a wrong place (not 2nd by Clue 1) by Clue 4.
- Conclusion: Digit 4 is incorrect. Also we know digit 1 incorrect.
Step 2: Identify one correct digit and its position
From Clue 1, 1st position goes to digit 2.
Clue 1: Code 2 4 1 : One digit right and in right position.
- Conclusion: Right digit 2 takes 1st place.
Step 3: Determine the other two correct digits and their positions
From Clue 5, digits 5, 7 are the two right. 5 and 7 can occupy either 2nd or 3rd.
Clue 5: Code 7 5 1 : Two digits right but wrongly placed.
- Conclusion: With digit 1 wrong, digits 5 and 7 are the other two correct digits with position either 2nd or 3rd.
From Clue 4 find the solution.
Clue 4: Code 3 4 7 : One digit right but wrongly placed.
- Conclusion: The single right digit 7 occupies a wrong 3rd position.
- Conclusion: Digit 7 must be in 2nd position (as 1st position is occupied by digit 2).
- Conclusion: Digit 5 must be in 3rd.
Correct code to open the number lock is 2 7 5.
The clues 2 and 3 not needed. This is the most efficient solution.
End note
The key to quick solution of reasoning puzzles is processing the most suitable clue or condition either individually or together with other clues.
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