A class has (2/3) hours. Student A spent about (1/3) of the whole time doing the experiment, and about (1/5) of the whole time was spent giving instructions by the teacher, and the rest of the time was used for homework. What fraction of the whole class is the time spent doing homework?
一节课有(2/3)小时．甲同学做实验大约用了全部时间的(1/3)，老师点拨大约用了全部时间的(1/5)，其余时间用来做作业．做作业的时间大约是整节课的几分之几？
<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>