The fifth grade students participate in the interest groups of the school. Those who participate in the mathematics group account for (1/3) of the whole class, and those who participate in the calligraphy group account for (1/5) of the whole class. What percentage of the whole class are the two groups?
五年级同学参加学校的兴趣小组，参加数学小组的占全班的(1/3)，参加书法小组的占全班的(1/5)，两个小组共占全班的几分之几？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/3) + (1/5)</gadget>
<output>8/15 = around 0.533333</output>

<result>8/15 = around 0.533333</result>