(2/5) of a number is 18, what is (5/9) of this number.
一个数的(2/5)是18，这个数的(5/9)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>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">45 * (5/9)</gadget>
<output>25</output>

<result>25</result>