Calculate total cost based on rate and duration like Hours,Minutes with C#
<p>I have a dropdown list to present the duration of a specific job with the format "hours,minutes":</p>

<pre><code>&lt;select class="form-control"&gt;
    &lt;option&gt;&lt;/option&gt;
    &lt;option&gt;0,10&lt;/option&gt;
    &lt;option&gt;0,20&lt;/option&gt;
    &lt;option&gt;0,30&lt;/option&gt;
    &lt;option&gt;0,40&lt;/option&gt;
    &lt;option&gt;0,50&lt;/option&gt;
    &lt;option&gt;1&lt;/option&gt;
    &lt;option&gt;1,10&lt;/option&gt;
    &lt;option&gt;1,20&lt;/option&gt;
    &lt;option&gt;1,30&lt;/option&gt;
    &lt;option&gt;1,40&lt;/option&gt;
    &lt;option&gt;1,50&lt;/option&gt;
&lt;/select&gt;
</code></pre>

<p>I have the rate hour:</p>

<pre><code>var rate = "8"; // 8 €
</code></pre>

<p>If the user selects for example "1,3", how can I calculate the total cost based on the rate? (in this case the total would be 12€)</p>