(2/3) of a number is 10, what is (1/5) of this number.
一个数的(2/3)是10，这个数的(1/5)是多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">10 / (2/3)</gadget>
<output>15</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">15 * (1/5)</gadget>
<output>3</output>

<result>3</result>