ISRO2014-52

Question

Consider the following grammar.

• $S \rightarrow AB$
• $A  \rightarrow a$
• $A  \rightarrow BaB$
• $B  \rightarrow bbA$

Which of the following statements is FALSE?

• A. The length of every string produced by this grammar is even
• B. No string produced by this grammar has three consecutive $a's$
• C. The length of substring produced by $B$ is always odd
• D. No string produced by this grammar has four consecutive $b's$

Answer 1

S->AB

S->aB

S->abbA

S->abbBaB

S->abbbbAabbA

S->abbbbaabba

Given Grammar can produce a string which has 4 consecutive b's.

Hence,Option(D)No string produced by this grammar has four consecutive b's.

Comments

u r right

---

I think all four options are false so no answer match..?.

---

sarbesh  You should read the question properly.

---

Option (C) can also be the answer.

S → AB → aB --> abbA → abba

This is a string with even length.

Answer 2

Answer : No string produced by this grammar has four consecutive b's

Answer 3

d option because here we can derive 4 consecutive b's

string abbbbaabba can be genrate which has 4 b's

Answer 4

how is option b not the answer ? any string for  b