SOURCE

<div class="three-column-layout">
    <div class="left"></div>
    <div class="center"></div>
    <div class="right"></div>
</div>

.three-column-layout {
    width: 400px;
    height: 400px;
    .left {
        float: left;
        width: 50px;
        height: 100%;
        background-color: #f66;
    }
    .center {
        float: left;
        width: 100px;
        height: 100%;
        background-color: #66f;
    }
    .right {
        overflow: hidden;
        height: 100%;
        background-color: #3c9;
    }
}