title: Ruby: Find Most Common Phrase in array of strings
body: <p>I'd like to be able to find the 10 most common questions in a array of 300-500 strings, in Ruby. </p>
  
  <p>An example element being </p>
  
  <blockquote>
    <p>["HI, I'd like your product. I just have one question. How do I change
    my password?", "Can someone tell me how I change my password?", "I
    can't afford this. How do I cancel my account?", "Account
    cancelation?", "I forgot my password, how do I change my password?",
    .....]</p>
  </blockquote>
  
  <p>Basically, I'm going to have an array of a lot of strings, and I have to extract the question, and find the 10 most common questions from that array.</p>
  
  <p>I've tried looking around (checked out n-grams, but it didn't seem too relevant) and have yet to come up with any ideas. </p>
  
  <p>Do you know of any algorithms you'd suggest I take a look at? A link to a couple examples would be terrific! </p>