Hey i'm having a little trouble with expected value so i don't really understand how to do this problem:

Assume that N people check their hats and the hats are handed back to them at random. Let X_j = 1 if the jth person gets his or her hat and 0 otherwise. Find E(X_j) and E(X_j * X_k) for j not equal to k. Are X_j and X_k independent?

Thanks!