1
GATE CSE 2020
Numerical
+2
-0
Consider the following language.

L = {x $$ \in $$ {a, b}* | number of a’s in x is divisible by 2 but not divisible by 3}

The minimum number of states in a DFA that accepts L is ______.
Your input ____
2
GATE CSE 2020
MCQ (Single Correct Answer)
+1
-0.33
Which one of the following regular expressions represents the set of all binary strings with an odd number of 1’s?
A
10*(0*10*10*)*
B
((0 + 1)*1(0 + 1)*1)*10*
C
(0*10*10*)*10*
D
(0*10*10*)*0*1
3
GATE CSE 2020
MCQ (Single Correct Answer)
+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
4
GATE CSE 2020
MCQ (Single Correct Answer)
+1
-0.33
Consider the language
L = { $${a^n}|n \ge 0$$ } $$ \cup $$ { $${a^n}{b^n}|n \ge 0$$ }
and the following statements.

I. L is deterministic context-free.
II. L is context-free but not deterministic context-free.
III. L is not LL(k) for any k.

Which of the above statements is/are TRUE?
A
I only
B
II only
C
I and III only
D
III only