Consider the following Boolean expression. F = (X + Y + Z)( X + Y)( Y + Z) Which of the following Boolean expressions is/are equivalent to F (complement of F)?
Topic-wise GATE CS PYQs with verified steps
GATE CSE 2021 Set 1 · Q42
Time
Select all that applyOne or more correct
Solution
Official answer: B) X Y + Z; C) (X + Z)( Y + Z); D) X Y + Y Z + X Y Z
Boolean Algebra and MinimizationGiven the Boolean expression in product-of-sums (POS) form:
First, simplify : Using the distributive law on :
Multiplying by :
Now, compute the complement using De Morgan's laws:
Now evaluate each option:
Option (A): is the dual of with complemented literals, which is not equivalent to .
Option (B): is directly identical to .
Option (C): , which matches .
Option (D): . By consensus between and , this simplifies to , which also matches .
Thus, options B, C, and D are correct.
Try the question first, then check your work.
Examiner trap
Simplify by factoring or considering the cases and , then use De Morgan's laws to find .
This Boolean Algebra and Minimization previous year question is Q42 of the GATE CSE 2021 Set 1 paper. Find more GATE CSE PYQs on Boolean Algebra and Minimization in Digital Logic, or browse all GATE CSE PYQs.
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Boolean Algebra and Minimization has 36 GATE CSE PYQs across 23 papers from 2011 to 2026. 6 of them are 2-mark MSQs like this one, and it is the only one in GATE CSE 2021 Set 1.
How GATE tests Boolean Algebra and MinimizationIndependent practice explanation verified by the GateAI team. GATE is conducted by the IITs; question text follows the official paper.