There are three piles of chess pieces, each pile has 42 pieces, and there are only black and white chess pieces. There are as many black stones in the first pile as there are white stones in the second pile, and the black stones in the third pile account for (3/7). If these three piles of chess pieces are put together, what is the percentage of white chess pieces in all the chess pieces?
有三堆棋子，每堆棋子42枚，并且只有黑白两色棋子．第一堆里的黑子和第二堆里的白子一样多，第三堆里的黑子占(3/7)，把这三堆棋子集中在一起，白棋子占全部棋子的多少
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">42 * (4/7)</gadget>
<output>24</output>

<gadget id="calculator">42 + 24</gadget>
<output>66</output>

<gadget id="calculator">42 * 3</gadget>
<output>126</output>

<gadget id="calculator">66 / 126</gadget>
<output>11/21 = around 0.52381</output>

<result>11/21 = around 0.52381</result>