(3/5) of number A is as much as 40% of number B, number B is 30, what is number A?
甲数的(3/5)与乙数的40%一样多，乙数是30，甲数是多少？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">(2/5) / (3/5)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">30 * (2/3)</gadget>
<output>20</output>

<result>20</result>