Made easy test series

Question

Please explain the why A and D are correct?

Comments

Only D should be correct.

and why C is incorrect: try this string “bab”, can you get it from C?

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I don’t understand why A is correct. I think only D is correct here.

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I was also getting only C...can u explain for D ?

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Option (A) is definitely wrong. it generate only $b.$ $(bb,bbb….)$ is not generated which is accepted by original FA.

Option (B) same. $bb.bbb..$ strings are not generated.

Option (C) is also incorrect. it will not generate strings like $(\epsilon, bab..)$ which is generated by given FA.

Option C and D expressions are the same but in option (D), the whole expression is enclosed with Kleen closure which is missing in Option (C) so it is wrong.

Option  (D) is correct.

Answer 1

Option (d) is the only correct answer here. Following points can be used to eliminate other 3 options

1. It cannot produce {bb, bbb, bbbb….} or empty string
2. It cannot produce {bb, bbb, bbbb….}
3. It cannot produce empty string
4. It can produce all strings of given DFA including {b, bb, bbb, bbbb….} and empty string