There are 72 people in a certain grade participating in two sports activities in the school, and each person must participate in at least one activity. Among them, (3/4) students participated in the tug-of-war competition, and the students participating in the rope skipping competition were (2/4) the number of students participating in the tug-of-war competition. 3) Then, how many people participated in both activities?
某年级有72人参加学校的两项体育活动，每人至少要参加一项活动，其中有(3/4)的同学参加了拔河比赛，参加跳绳比赛的同学是参加拔河比赛人数的(2/3)，那么，这两项活动都参加的有多少人？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">72 * (3/4) * (2/3)</gadget>
<output>36</output>

<gadget id="calculator">72 - 36</gadget>
<output>36</output>

<gadget id="calculator">72 * (3/4)</gadget>
<output>54</output>

<gadget id="calculator">72 - 54</gadget>
<output>18</output>

<gadget id="calculator">36 + 18</gadget>
<output>54</output>

<result>18</result>