Class 51 carries out extracurricular activities. (1/4) of the class participates in table tennis activities, (1/2) of the class participates in hand-holding activities, and the others participate in rope skipping activities. What percentage?
五一班开展课外活动，全班人数的(1/4)参加乒乓球活动，全班人数的(1/2)参加拉手活动，其他的参加了跳绳活动，参加跳绳活动的是全班人数的几分之几？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/2) - (1/4)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>