title: replace specific text in ruby using regex
body: <p>In ruby, I'm trying to replace the below url's <strong>bolded</strong> portion with new numbers:</p>
  
  <blockquote>
    <p>/ShowForum-g1-i12105-<strong>o20</strong>-TripAdvisor_Support.html</p>
  </blockquote>
  
  <p>How would I target and replace the <strong>-o20-</strong>
  with -o30- or -o40- or -o1200- while leaving the rest of the url
  intact? The urls could be anything, but I'd like to be able to find this exact pattern of -o20- and replace it with whatever number I want. </p>
  
  <p>Thank you in advance. </p>