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According to the Principle of duality, the Boolean equation will be equivalent to:
According to the Principle of duality, the Boolean equation $(A' + B) \cdot (1 + B) = A' + B$ will be equivalent to:
- (a)$(A + B') \cdot (0 + B) = A + B'$
- (b)$(A' \cdot B) + (0 \cdot B) = A' \cdot B$
- (c)$(A' \cdot B) + (0 \cdot B) = A' + B$
- (d)$(A' + B) \cdot (0 + B) = A' + B$
Answer
Answer
Official answer keyCorrect option: (b)
Answer: (b) $(A' \cdot B) + (0 \cdot B) = A' \cdot B$
By the Principle of Duality, every $+$ is replaced by $\cdot$, every $\cdot$ by $+$, and every $1$ by $0$ (and vice versa), leaving the variables unchanged. Applying this to $(A'+B)\cdot(1+B)=A'+B$ gives $(A'\cdot B)+(0\cdot B)=A'\cdot B$.
From ISC 2025 Specimen Computer Science Paper 1, question 1(iii).