Students in Class 5 and 3 expressed their holiday blessings to their mothers on Mother's Day. Among them, (1/3) students sent flowers, (1/5) students gave their mother a fragrant kiss, and the rest of the students sent homemade greeting cards. What percentage of the class are students who send homemade greeting cards?
五3班的同学在母亲节都表达了对妈妈的节日祝福．其中，(1/3)的同学送了鲜花，(1/5)的同学给了妈妈一个香香的吻，其余的同学都送上了自制的贺卡．送自制贺卡的同学占全班的几分之几？
<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 - (1/3) - (1/5)</gadget>
<output>7/15 = around 0.466667</output>

<result>7/15 = around 0.466667</result>