## Regular expression for language It should contain at least 3 one

Regular expression for language it should contain at least 3 one. => (0+1)*1(0+1)*1(0+1)*1(0+1)*

## Regular expression for any number of a followed by any number of b followed by any number of c

Regular expression for any number of a followed by any number of b followed by any number of c => a*b*c*

## Regular expression for ∑={a,b} such that 3rd character from right end of the string is always a

Regular expression for ∑={a,b} such that 3rd character from right end of the string is always a =>  (a+b)*a(a+b)(a+b)

## Regular expression for language which consist of exactly two b’s over the set ∑={a,b}

Regular expression for language which consist of exactly two b’s over the set ∑={a,b} =>  a*ba*ba*

## Regular expression for all binary string with at least 3 characters and 3rd character should be zero

Regular expression for all binary string with at least 3 characters and 3rd character should be zero =>  (0+1)(0+1)0(0+1)*

## Regular expression for string start with 1 and end with 0

Regular expression for string start with 1 and end with 0 =>  1(0+1)*0

## Regular expression for string end with abb

Regular expression for string end with abb =>(a+b)*abb

## Regular expression for string of 0 and 1 end with 00

Regular expression for string of 0 and 1 end with 00 => (0+1)*00

## Regular expression for string starts and ends with same character

Regular expression for String starts and ends with same character 0(0+1)*0     or 1(0+1)*1 or a(a+b)*a or b(a+b)*b

## Regular expression for binary number starts and end with 1

Regular expression for binary number starts and end with 1. => 1(0+1)*1