There are (2/3) hours in a class, (1/5) hours for students to discuss, (3/10) hours for teachers to explain, and the rest of the time for homework. How long did it take you to do the homework?
一节课有(2/3)小时，学生讨论用(1/5)小时，教师讲解用(3/10)小时，剩下的时间用来做作业．做作业用了多长时间？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(2/3) - (1/5) - (3/10)</gadget>
<output>1/6 = around 0.166667</output>

<result>1/6 = around 0.166667</result>