Hey guys, having trouble with the following question.

Let A = {1,2,3,4},

a) how many relations are there on A?

My answer: $\displaystyle \mathcal{P}(A \cdot A)$ = $\displaystyle 2^{4 \cdot 4}$ = $\displaystyle 2^{16}$

b) How many equivalent relations are there on A?

My answer:Im not sure about this one. Any help?