Equal width columns with no outside margin

by secretgspot

HTML

<div></div>
<div></div>
<div></div>

CSS

body {
    margin: 0;
    padding: 0;
}
div {
    background: red;
    float: left;
    margin-left: 5%;
    min-height: 300px;
    width: 30%;
}
div:first-child {
    margin-left: 0;
}