A's age is B's (4/5), B's age is C's (2/3), then A's age is C's age.
甲的年龄是乙的(4/5)，乙的年龄是丙的(2/3)，则甲的年龄是丙的年龄的多少．
<gadget id="calculator">8 / 15</gadget>
<output>8/15 = around 0.533333</output>

<result>8/15 = around 0.533333</result>