(2/5) of a number is 18, what is this number?
一个数的(2/5)是18，这个数是多少．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">18 / (2/5)</gadget>
<output>45</output>

<result>45</result>