(2/3) of a number is equal to 40% of 30. What is this number?
一个数的(2/3)等于30的40%．这个数是多少？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/5) / (2/3)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">30 * (3/5)</gadget>
<output>18</output>

<result>18</result>