Boolean Algebra Example 2 Questions and Answers

In this Boolean example, you have a logic diagram consisting of gates, and your job is to find a Boolean expression that describes it. Once you have that, you should simplify it to minimize the number of gates it uses.

Intermediate Terms

We start by writing the expressions for individual gates and their intermediate terms.

Using De Morgan's Theorem

As you can see, there is that familiar term that requires De Morgan’s theorem, which we substitute into our equation.

Substitution Stage

We now substitute for the D and E terms using expressions figured out previously. At this stage, we also get these double bars over our terms, which is like double negation. If you NOT something twice, then it negates itself.

Simplified Formula

Finally, the answer is a three input AND gate, which does the same job.


Truth Table

ABCDEQ
000110
001110
010110
011100
100010
101010
110010
111001

As you can see from the truth table, A AND B AND C gives the result in the Q column.

This Article Continues...

Boolean Algebra
De Morgan's Theorem
XOR Gate
EXOR Gate
XNOR Gate
Example 1 Questions and Answers
Example 2 Questions and Answers