Hi ... here's a tricky situation that I'm in ... its best explained with an example

I want to write a rule that will select an element only if it is of class "about-banner" and of class "third" from the following HTML

<div class="about-banner"></div>
<div class="third"></div>
<div class="about-banner third">This is the one I want to select</div>
<div class="about-banner half"></div>
<div class="about-banner quarter"></div>

How do I write it? My instinct would be to write

.about-banner.third {}


.about-banner && .third {}

If its not possible thats cool, just would like to know. Thanks in advance

edit post:
I know that I could wrap it in a container
<div class="about-banners"> ... </div>
.about-banners .third {}
but I'm trying to avoid doing so