Best way to represent 1/3rd of 100% in CSS?

http://stackoverflow.com/questions/5158735

by Marcel

HTML

<div id="wrap">
    <div class="col"></div>
    <div class="col gut"></div>
    <div class="col"></div>
</div>

CSS

body { background:#eee; }
#wrap { width:80%; margin:1em auto; padding:30px; overflow:hidden; background:#fff; min-width:30em; max-width:50em; }
.col { float:left; width:30%; height:300px; background:#ddd; }
.gut { margin:0 5%; }