I got this question during an online exam.
Question is from Number Theory in portion More Number Theory of Cryptograph & Network Security
The explanation is: Use Fermats Theorum. Fermat’s Theorem states that if p is prime and a is a positive integer not divisible
by p, then a^(p–1) = 1 (mod p). Therefore 3^10 = 1 (mod 11). Therefore
3^201 = (3^10)^20 x 3 = 3 (mod 11).