(1/2) of (2/3) of a number is 20, what is this number?
一个数的(2/3)的(1/2)是20，这个数是多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(2/3) * (1/2)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">20 / (1/3)</gadget>
<output>60</output>

<result>60</result>