Question

Consider the logic circuit with inputs A,B,C, and output Y. How many combinations of A, B and C give the output Y=0?

• A. 8
• B. 5
• C. 7
• D. 1

Answer 1

Answer: (C)

7

Answer 2

In a logic circuit with inputs A, B, and C, and an output Y, the values of A, B, and C can be either 0 or 1. The output Y is determined based on the logic gates and connections within the circuit.

To find the combinations of A, B, and C that give the output Y = 0, we need to identify the specific input combinations that result in an output of 0.

Since there are two possible values (0 and 1) for each of the three inputs (A, B, C), there are a total of 23=823=8 possible input combinations.

For the output Y to be 0, we need to determine the input combinations that lead to Y = 0. There are seven combinations in which the output is 0:

1. A = 0, B = 0, C = 0
2. A = 0, B = 0, C = 1
3. A = 0, B = 1, C = 0
4. A = 1, B = 0, C = 0
5. A = 0, B = 1, C = 1
6. A = 1, B = 0, C = 1
7. A = 1, B = 1, C = 0

These combinations are obtained by considering the logical operations within the circuit that lead to an output Y = 0.

Hence, there are 7 combinations of A, B, and C that result in the output Y = 0.

The correct answer is option (C): 7