Question

Which one of the following languages over the alphabet $\{0,1\}$ is described by the regular expression: $(0+1{)}^{\ast }0(0+1{)}^{\ast }0(0+1{)}^{\ast }?$

• A. The set of all strings that begin and end with either 0 or 1
• B. The set of all strings containing the substring 00
• C. The set of all strings containing at least two 0's
• D. The set of all strings containing at most two 0's

Answer 1

The correct option is C The set of all strings containing at least two 0's

$(0+1{)}^{\ast }0(0+1{)}^{\ast }0(0+1{)}^{\ast }$ is the regular expression for atleast two zero's.