There are 60 students in Class 1, each of whom participates in at least one interest group, among which (2/3) participate in the sports interest group, and (1/2) participate in the mathematics interest group. At least how many people participated in both groups?
六一班共有学生60人，每人至少参加一个兴趣小组，其中(2/3)的人参加体育兴趣小组，(1/2)的人参加数学兴趣小组．两个小组都参加的至少有多少人？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) - 1</gadget>
<output>-1/2 = around -0.5</output>

<gadget id="calculator">(2/3) + (-1/2)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">60 * (1/6)</gadget>
<output>10</output>

<result>10</result>