How to center images in div

Problem :

How to make these images stay in center? Here are my css and html codes.

My html code:

<div id="logos">
<div id="q">
<img id="round" src="img/i1.jpg" />
<img id="round" src="img/i1.jpg" />
<img id="round" src="img/i1.jpg" />
</div>
</div>

My css code:

#logos {
display: inline-block;
width:100%;
}

#q{
 display: block;

 }
 #round {
 border-radius: 50%;
 display: inline;
 margin: 0 5px;
 width: 150; 
 height: 150; 
 position: cetner;
}

Solution :

Use text-align: center on the parent...

#q{
    display: block;
    text-align: center;
 }

.round {
    border-radius: 50%;
    display: inline;
    margin: 0 5px;
    width: 150px; 
    height: 150px; 
}

<div id="logos">
    <div id="q">
        <img class="round" src="http://placehold.it/150x150" />
        <img class="round" src="http://placehold.it/150x150" />
        <img class="round" src="http://placehold.it/150x150" />
    </div>
</div>

Also, ID's must be unique. rounded should be a class not an ID.

Secondly, position: center; doesn't exist in CSS.

And finally, width: 150 and height: 150 must have a unit of measurement (probably px) though this will have no effect because the elements are inline - perhaps you meant inline-block?