A group of students went rowing, and they calculated, if one more boat is added, each boat can take exactly 6 people, if one boat is reduced, each boat can take exactly 9 people, then how many students are there in the class.
有一批同学去划船，他们算了一下，如果增加一条船，正好每船坐6人，如果减少一条船，正好每条船坐9人，则该班有多少名同学．
<gadget id="calculator">9 + 6</gadget>
<output>15</output>

<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<gadget id="calculator">6 * 5</gadget>
<output>30</output>

<gadget id="calculator">30 + 6</gadget>
<output>36</output>

<result>36</result>