Question: What is the modular inverse of 3 modulo 11?

Options:

1. 4
2. 7
3. 8
4. 9

Correct Answer: 4

Solution:

The modular inverse of 3 mod 11 is a number x such that 3x ≡ 1 (mod 11). The solution is x = 4, since 3 * 4 = 12 ≡ 1 (mod 11).