Difficulty: Easy
Correct Answer: 7
Explanation:
Introduction / Context:Understanding OR gate behavior across all input states is foundational for designing combinational logic and estimating probabilities of output activity.
Given Data / Assumptions:
Concept / Approach:The only case that yields a LOW output for an OR gate is when all inputs are LOW simultaneously. Every other combination produces a HIGH output.
Step-by-Step Solution:Total combinations = 8.LOW output cases = exactly 1 (000).HIGH output cases = 8 − 1 = 7.
Verification / Alternative check:Enumerate: 001, 010, 011, 100, 101, 110, 111 → all yield HIGH, confirming seven HIGH outputs.
Why Other Options Are Wrong:1 or 2: underestimate the number of HIGH cases.8: includes the all-zero case, which produces LOW for an OR.
Common Pitfalls:Forgetting the all-zero case or confusing OR with NOR or AND behavior.
Final Answer:7
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