3. The adder-subtractor has the following values for mode input M and data inputs A and B: M A B (a)0 1100 1000 (b) 0111 0110 (c) 1 0000 0001 (d) 0 0101 1010 In each case, determine the values of the SUM outputs, the carry C, and overflow V. 4. Assume that the exclusive-OR gate has a propagation delay of 15ns and that the AND and OR gates have a propagation delay of 10 ns. (a) What is the propagation delay time of following 1-bit full adder? (b) What is the total propagation delay time of a 4-bit ripple carry adder built using the 1-bit full adder? (c) What is the total propagation delay time of a 4 bit carry lookahead adder? CIN Cou OUT 1-bit adder