(3/4) of A is equal to (4/5) of B, and B is the number of A.
甲数的(3/4)等于乙数的(4/5)，乙数是甲数的多少．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / (3/4)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">1 / (4/5) / (4/3)</gadget>
<output>15/16 = around 0.9375</output>

<result>15/16 = around 0.9375</result>