List of top Mathematics Questions on Operations on Sets asked in WBJEE

Let A,B,C are subsets of set X. Then consider the validity of the following set theoretic statement:

Let A be a set containing n elements, A subset P of A is chosen and set A is reconstructed by replacing the elements of P. A subset Q of A is chosen again. The number of ways of choosing P and Q such that Q contains just one element more than P is