I need help with these questions. Please answer them for me so that I can verify my answer is correct.

Question 4 How many elements are in the power set of the empty set? O 2 O 4 Oo O 1 Question 5 Assuming an alphabet Z = (a, b], and a language L consisting of all strings of length s 3, how many strings does L contain? O 15 O 16 O 8 O 3 Question 6 Assume |A| = 3 and |B| = 4, what is |A x B|? O 12 O 18 O7 O 24