has A years old, B's age is A's (1/3), A and B have a total of A + how many A years old.
甲有A岁，乙的岁数是甲的(1/3)，甲、乙共A+多少A岁．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>