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UPSC Civil ServicesPrelims2022General Studies Paper II (CSAT)
Question
QQ55. There is a numeric lock which has a 3-digit PIN. The PIN contains digits 1 to 7. There is no repetition of digits. The digits in the PIN from left to right are in decreasing order. Any two digits in the PIN differ by at least 2. How many maximum attempts does one need to find out the PIN with certainty?
Options
- A 6
- B 8
- C 10
- D 12
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Correct Answer
C 10
Model Answer
Answer: option C, as per UPSC's final answer key (Series A).