In the inter-class activities, (1/3) of the students in Class 1 participated in the rope skipping activity, 25% of the students participated in the table tennis activity, and the remaining 15 students all participated in the football activity. How many students participated in the table tennis activity?
课间活动中，六1班有(1/3)的学生参加跳绳活动，25%的学生参加乒乓球活动，剩下的15人全部参加足球活动，参加乒乓球活动的学生有几人？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/3) - (1/4)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">15 / (5/12)</gadget>
<output>36</output>

<gadget id="calculator">36 * (1/4)</gadget>
<output>9</output>

<result>9</result>