title: replace the last word
body: <p>i want to replace the last string as ""..</p>
  
  <p>Eg:-here the string is <strong>apple and mango and</strong>
  the output should be <strong>apple and mango</strong></p>
  
  <p>if the last word is OR, NOT, AND i have to replace that to ""....</p>
  
  <p>Thanks in advance....  </p>