相关疑难解决方法(0)

div {
  border: 1px solid
}

<div id="col_1" style="float:left;width:150px;">1</div>
<div id="col_2" style="float:left;width:100px;">2</div>
<div id="col_3" style="float:left;width:<REMAINING_WIDTH>;">3</div>