Tryit Editor v1.8

Source Code:
<!DOCTYPE html> <html> <head> <script src="../../ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"> </script> <script> $(document).ready(function(){ $("p:nth-of-type(3n+2)").css("background-color","yellow"); }); </script> </head> <body> <p>The p:nth-child(3n+2) selects each 3rd paragraph, starting at the 2nd paragraph. <div style="border:1px solid;"> <span>This is a span element.</span> <p>The first paragraph.</p> <p>The second paragraph.</p> <p>The third paragraph.</p> <p>The fourth paragraph.</p> <p>The fifth paragraph.</p> <p>The sixth paragraph.</p> <p>The seventh paragraph.</p> <p>The eight paragraph.</p> </div><br> </body> </html>
Result:
W3Schools.com - Try it yourself