For the logic circuit shown, the output waveform at Y is

Step-by-step solution

All the gates used in the diagram represent NAND gates. Thus, the output Y can be calculated as follows Y = A · B =   A + B =   A + B The above equation suggests that the output of the given combination yields the same result as an OR gate. The truth table can be written as follows A B A B Y = A · B 0 0 1 1 0 0 1 1 0 1 1 0 0 1 1 1 1 0 0 1 Hence, this is the correct output.