In a class, students spend (1/3) hours doing experiments, the teacher spends (1/5) hours explaining, and the rest of the time students do homework independently. It is known that each class is (2/3) hours, how many hours did the students spend doing their homework independently?
一堂课上，学生做实验用(1/3)小时，老师讲解用(1/5)小时，其余的时间学生独立做作业．已知每堂课是(2/3)小时，学生独立做作业用了多少小时？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<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">(2/3) - (1/3) - (1/5)</gadget>
<output>2/15 = around 0.133333</output>

<result>2/15 = around 0.133333</result>