1
GATE CSE 2020
+1
-0.33
Consider the following statements.

I. If L1 $$\cup$$ L2 is regular, then both L1 and L2 must be regular.
II. The class of regular languages is closed under infinite union.

Which of the above statements is/are TRUE?
A
I only
B
II only
C
Both I and II
D
Neither I nor II
2
GATE CSE 2019
+1
-0.33
If L is a regular language over Σ = {a,b}, which one of the following languages is NOT regular?
A
Suffix (L) = {y ∈ Σ* such that xy ∈ L}
B
{wwR │w ∈ L}
C
Prefix (L) = {x ∈ Σ*│∃y ∈ Σ* such that xy ∈ L}
D
L ∙ LR = {xy │ x ∈ L, yR ∈ L}
3
GATE CSE 2019
+1
-0.33
For Σ = {a, b}, let us consider the regular language L = {x | x = a2+3k or x = b10+12k, k ≥ 0}. Which one of the following can be a pumping length (the constant guaranteed by the pumping lemma) for L?
A
9
B
5
C
24
D
3
4
GATE CSE 2016 Set 2
Numerical
+1
-0
The number of states in the minimum sized $$DFA$$ that accepts the language defined by the regular expression $${\left( {0 + 1} \right)^ * }\left( {0 + 1} \right){\left( {0 + 1} \right)^ * }$$\$
is ___________________.