The (5/6) of the B number is the A number, and the (4/5) of the C number is the B number. What fraction of the C number is the A number?
乙数的(5/6)是甲数，丙数的(4/5)是乙数，甲数是丙数的几分之几？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 / (4/5)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(5/6) / (5/4)</gadget>
<output>2/3 = around 0.666667</output>

<result>2/3 = around 0.666667</result>