title: Counting how many numbers are divisible by 3 in a list using recursion?
body: <p>This is confusing me a lot here, I thnk I have an OK knowledge in haskell but I just cant get the whole "counting" part to work.</p>
  
  <pre><code>recursion :: [Int] -&gt; Int
  recursion [] = []
  recursion (x:xs) = if x `mod` == 3 then.. +1 +  recursion xs
  </code></pre>
  
  <p>I know where its going wrong, the whole then +1 part but just cannot do it</p>
  
  <p>count how many numbers are divisible by 3 in a giving list.</p>