In a 40-minute math class, students spend (2/5) time performing experiments. How much time did students spend performing experiments?
在一堂40分钟的数学课中，学生操作实验的时间占(2/5)，学生操作实验用了多少时间？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">40 * (2/5)</gadget>
<output>16</output>

<result>16</result>