There are three piles of Go pieces, each with an equal number of pieces. There are as many black stones in the first pile as there are white stones in the second pile, and (2/5) of all the black stones in the third pile. Then, among the three piles of chess pieces, what percentage of the total number of white pieces account for all the pieces?
有三堆围棋子，每堆棋子数相等．第一堆中的黑子与第二堆中的白子一样多，第三堆中的黑子占全部黑子的(2/5)．那么，三堆棋子中，白子总数占全部棋子的几分之几？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(1/3) / (3/5)</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">1 - (5/9)</gadget>
<output>4/9 = around 0.444444</output>

<result>4/9 = around 0.444444</result>