52) An example of a universal building block is:

53) The dual of the switching function x + yz is:

54) The characteristic equation of D flip-flop is:

55) If four 4 input multiplexers drive a 4 input multiplexer, we get a:

56) Which of the following respectively represent commutative law, Associative law and Distributive law ?
I. A.(B C)=(A.B).C
II. A.(B+C)=A.B+A.C
III. A + B = B + A