The time for a class is (2/3) hours, and the time for doing experiments is (3/5), how many hours are used for doing experiments.
一节课的时间是(2/3)小时，做实验的时间占了(3/5)，做实验用了多少小时．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(2/3) * (3/5)</gadget>
<output>2/5 = around 0.4</output>

<result>2/5 = around 0.4</result>