<div class="centerDiv">
<div class="div1 red">
</div>
<div class="div1 blue">
</div>
<div class="div1 yellow">
</div>
</div>
.centerDiv {
width: 60%;
height: 100px;
margin: 0 auto;
}
.div1 {
width: 30%;
border: 1px solid #000000;
height:100%;
float:left;
background-color:white;
}
.div1.red {
background-color:red;
}
.div1.blue {
background-color:blue;
}
.div1.yellow {
background-color:yellow;
}