Exercise · ZW-WILSON-S-THEOREM-009 · ★★★ Advanced
Knowing that \(12! \equiv -1 \pmod{13}\), find the remainder of \(11!\) when divided by \(13\).
Choose one option.
Show answer
- B. \(1\)
Explanation
Since \(12! = 12\cdot 11!\) and \(12 \equiv -1 \pmod{13}\), we get \(-11! \equiv -1\), so \(11! \equiv 1 \pmod{13}\).
Review the concept: Wilson's theorem
For a prime number \(p\), \((p-1)!\) leaves remainder \(-1\) when divided by \(p\).
\[(p-1)!\equiv -1 \pmod{p}\]
More practice problems: wilson's theorem
- ZW-WILSON-S-THEOREM-001 What does Wilson's theorem state?
- ZW-WILSON-S-THEOREM-002 What is the remainder of 4! when divided by 5?
- ZW-WILSON-S-THEOREM-003 In Wilson's theorem, what condition must p satisfy?
- ZW-WILSON-S-THEOREM-004 For p = 3, what is 2! modulo 3?
- ZW-WILSON-S-THEOREM-005 What does (p-1)! ≡ -1 pmodp mean?
- ZW-WILSON-S-THEOREM-006 If n>1 satisfies (n-1)!≡ -1 pmodn, what can you conclude about n?
- ZW-WILSON-S-THEOREM-007 Modulo 7, which elements of \1,2,dots,6\ are their own inverses?
- ZW-WILSON-S-THEOREM-008 What is (p-1)! + 1 modulo p for p = 5?