(2/7) of a number is 10, what is (3/5) of this number.
一个数的(2/7)是10，这个数的(3/5)是多少．
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">10 / (2/7)</gadget>
<output>35</output>

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

<gadget id="calculator">35 * (3/5)</gadget>
<output>21</output>

<result>21</result>