In a hotel, the number of rooms on each floor is the same. If there are 7 rooms on each floor, 6 rooms will be vacated in total; if there are only 5 rooms on each floor, 18 rooms will be vacant. Question: Is there a room on each floor?
一个旅店里，每层的房间数相同，如果每层有7间住人，一共空出6间房；如果每层只有5间住人，就会空出18间房．请问：每层有间房？
<gadget id="calculator">18 - 6</gadget>
<output>12</output>

<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<gadget id="calculator">6 * 7</gadget>
<output>42</output>

<gadget id="calculator">42 + 6</gadget>
<output>48</output>

<gadget id="calculator">48 / 6</gadget>
<output>8</output>

<result>8</result>