The logic operations of two combinational circuits in Figure-I and Figure-II are

Figure-I consists of two NOR gates. The first gate takes inputs X and Y, producing output (X+Y)'. This output along with input X feeds into the second NOR gate. The final expression is ((X+Y)' + X)'. Applying De Morgan's laws: (X+Y) · X' = XX' + YX' = 0 + XY' = XY'. Figure-II consists of a NAND gate with inputs X and Y (inverted). The output expression is (X · Y')'. Applying De Morgan's laws: X' + (Y')' = X' + Y. Comparing the results, XY' is not equivalent to X' + Y. Thus, the logic operations of the two circuits are different.