A is B's (2/3), C is B's (4/5), then how much is C's A's.
A是B的(2/3)，C是B的(4/5)，那么C是A的多少．
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 * (2/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(4/5) / (2/3)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">1 * (6/5)</gadget>
<output>6/5 = around 1.2</output>

<result>6/5 = around 1.2</result>