Boolean simplification (sum-of-products): Simplify the expression AB + A'B to its simplest form using Boolean algebra laws.

Difficulty: Easy

Correct Answer: B

Explanation:


Introduction / Context:
Simplifying Boolean expressions reduces gate count, power, and delay. The expression AB + A'B is a common pattern that can be minimized using standard identities. Recognizing these patterns is essential in manual algebra and when checking tool results.



Given Data / Assumptions:

  • Expression: F = AB + A'B (where A' denotes NOT A).
  • Variables A and B are independent Boolean variables.
  • Goal: obtain the simplest logically equivalent form.


Concept / Approach:
Use the Distributive and Absorption laws. Note that both product terms share B. Factor B, then apply the Complementarity law A + A' = 1. This often collapses the expression to a single literal or a simpler term.



Step-by-Step Solution:

Start with F = AB + A'B.Factor B: F = (A + A') * B.Use complementarity: A + A' = 1.Therefore F = 1 * B = B.


Verification / Alternative check:
Truth-table check: when B = 0, both AB and A'B are 0 → F = 0; when B = 1, either A or A' is 1 → AB + A'B = 1 → F = 1. This matches F = B for all A.



Why Other Options Are Wrong:

A + B: Overstates the function; when A=1, B=0 this yields 1, but original F=0.AB: Too restrictive; when A=0, B=1 original F=1 but AB=0.A'B: Only covers the A=0, B=1 case, not A=1, B=1 which also yields 1.


Common Pitfalls:
Forgetting to factor the common literal; misreading A'B as A + B; confusing A + A' (which equals 1) with A * A' (which equals 0).


Final Answer:
B

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