GATE 2025 CS1 Q.19: official answer

GATE 2025 · CS1Q.19 · 1 mark · MCQ

Consider the following context-free grammar $G$ , where $S$ , $A$ , and $B$ are the variables (non-terminals), $a$ and $b$ are the terminal symbols, $S$ is the start variable, and the rules of $G$ are described as:

$S \to aa B ∣ A bb$
$A \to a ∣ a A$
$B \to b ∣ b B$

Which ONE of the languages $L (G)$ is accepted by $G$ ?

(A)
$L (G) = {a^{2} b^{n} ∣ n \geq 1} \cup {a^{n} b^{2} ∣ n \geq 1}$
(B)
$L (G) = {a^{n} b^{2 n} ∣ n \geq 1} \cup {a^{2 n} b^{n} ∣ n \geq 1}$
(C)
$L (G) = {a^{n} b^{n} ∣ n \geq 1}$
(D)
$L (G) = {a^{2 n} b^{2 n} ∣ n \geq 1}$

See the question in the paper

GATE 2025 CS1 question 19

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Official answer

Official answer: ASource: Official answer key, GATE 2025 CS1 (IIT Roorkee)

From the GATE 2025 CS1 paper. Every question of this paper · Download the full paper · All 9 CFG & PDA questions, with notes

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