UGC NET CSE | December 2018 | Part 2 | Question: 7

Question

The boolean expression $\overline{A} \cdot B + A \cdot \overline{B}+ A \cdot B$ is equivalenet to

• A. $\overline{A} \cdot B$
• B. $\overline{A+B}$
• C. $A \cdot B$
• D. $A+B$

Answer 1

A'.B + A.B' + A.B

=A'.B + A.B + A.B'

=B(A' + A) + A.B'

=B + A.B'

=(B+A).(B+B')

=B+A

Option(d)

Comments

In 2nd last line, I used postulate 4

Answer 2

Can also be solved using K-map very easily.

Ans: D