There are 3 piles of Go pieces, each with 60 pieces. There are as many black pieces in the first pile as there are white pieces in the second pile, and half of the third pile is white pieces. How many white pieces are there in these three piles of chess pieces?
有3堆围棋子，每堆60枚．第一堆的黑子和第二堆的白子同样多，第三堆有一半是白子．这三堆棋子一共有白子多少枚．
<gadget id="calculator">60 / 2</gadget>
<output>30</output>

<gadget id="calculator">60 + 30</gadget>
<output>90</output>

<result>90</result>