<div id="carousel_1" class="carousel slide">
    <a href="#carousel_1" class="left carousel-control" data-slide="prev"></a>
    <a href="#carousel_1" class="right carousel-control" data-slide="next"></a>
</div>
<div id="carousel_2" class="carousel slide">
    <a href="#carousel_2" class="left carousel-control" data-slide="prev"></a>
    <a href="#carousel_2" class="right carousel-control" data-slide="next"></a>
</div>

$list = explode("/", "46/120");

$a = $list[0];
$b = $list[1];
...