There are 80 people in the school chorus, among which sixth grade students account for 2/5 of the total number of chorus members, fourth grade students account for 3/8 of the total number of chorus members, and the rest are fifth grade students. What percentage of students are in the grade?
学校合唱队有80人，其中六年级学生占合唱队总人数的(2/5)，四年级学生占合唱队总人数的(3/8)，其余的是五年级学生，合唱队中我们五年级的学生占几分之几？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 - (2/5) - (3/8)</gadget>
<output>9/40 = around 0.225</output>

<result>9/40 = around 0.225</result>