Class 5 and Class 3 participate in English and art interest groups, and each person participates in at least one of them. The number of people participating in the English group accounts for (2/3) of the whole class, and the number of people participating in the art group accounts for (3/5) of the whole class. What percentage of the class are those who participated in both groups?
五3班同学参加英语和美术兴趣小组，每人至少参加一项，参加英语小组的人数占全班同学的(2/3)，参加美术小组的人数占全班同学的(3/5)，两个组都参加的人数占全班同学的几分之几？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) - 1</gadget>
<output>-2/5 = around -0.4</output>

<gadget id="calculator">(2/3) + (-2/5)</gadget>
<output>4/15 = around 0.266667</output>

<result>4/15 = around 0.266667</result>