the <img> tag into the <td> cant't display

[pipti]

Hi: The following code ,the img cant't display：

<table>
    <tr><td >
        <img src="examples/example1/a.png" style="width:10%"/>
    </td></tr>
</table>

but if the style width is the px,can display.

The following code ,the img can display：

<div><img src="examples/example1/a.png" style="width:10%"/></div>