The number (2/5) of A is 40, what is the number of A?
甲数的(2/5)是40，甲数是多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<result>100</result>