The output of a three input (A, B, and C) AND gate is connected to a two input OR gate. A second input to the OR gate is labeled D. The Boolean expression representing this logic circuit is:
A) X = ABC + D
B) X = (A + B + C) + D
C) X = (ABC)D
D) X = (A + B + C) D

Question

Quizplus · Accepted Answer

The AND gate output is the product (AND operation) of its inputs A, B, and C, represented as ABC. This output is then input to an OR gate along with D, making the overall expression ABC + D, where "+" denotes the OR operation.

The Output of a Three Input (A, B, and C)