(4/5) of a number is 60, what is (6/7) of this number.
一个数的(4/5)是60，这个数的(6/7)是多少．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">60 / (4/5)</gadget>
<output>75</output>

<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">75 * (6/7)</gadget>
<output>450/7 = around 64.285714</output>

<result>450/7 = around 64.285714</result>