(1/4) of a is 25, then what is (2/5) of a.
a的(1/4)是25，那么a的(2/5)是多少．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">25 / (1/4)</gadget>
<output>100</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">100 * (2/5)</gadget>
<output>40</output>

<result>40</result>