<p><span style="color:#27ae60;"><span style="font-size:20px;">Solving the Problem</span></span></p>
<p>To solve this problem, we use the <span style="color:#8e44ad;">Choice Method</span>, which entails determining the number of choices we have in each "slot" and then multiplying those numbers together to get our final answer. In this problem, we have three "slots" because we're trying to create three-digit positive integers. In the first slot, we have three choices: $3$, $4$, and $8$. In the second slot, we only have two choices (because we used one of the numbers in the first slot). In the final slot, we have only one choice. This can be modeled in the following way:</p>
<p style="text-align: center;"><img alt="" src="https://gregmatapi.s3.amazonaws.com/media/misc/files/question6.PNG" style="width: 300px; height: 109px;" /></p>
<p><span style="font-size:16px;"><strong>Alternative Method</strong></span></p>
<p>Because we're only dealing with three possible digits, you can use a <span style="color:#8e44ad;">Brute Force</span> method, which involves listing out all possibilities: </p>
<ul>
<li>$348$</li>
<li>$384$</li>
<li>$438$</li>
<li>$483$</li>
<li>$834$</li>
<li>$843$</li>
</ul>
<p>In both cases,<strong> <span style="color:#27ae60;">the correct answer is B</span></strong>.</p>