Fermat's states that if p is a prime number and a is an integer not divisible by p then a^(p-1)=1(mod p)
or the modification of fermat's theorem is that a^p=a (mod p)
we have given 3^12mod11 , we know that 11 is prime number ,
so using fermat's theorem we can say that 3^11=3mod 11
so the question become (3 mod 11) * (3 mod 11) = 9 mod 11 = 9