There are three piles of chess pieces, 50 pieces in each pile. The number of black stones in the first pile is the same as that of white stones in the second pile, and half of the third pile is white. How many black stones are there in total in this pile?
三堆棋子，每堆50枚，第一堆的黑子与第二堆的白子同样多，第三堆有一半是白子，这堆棋子一共有多少枚黑子．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">50 * (1/2)</gadget>
<output>25</output>

<gadget id="calculator">50 + 25</gadget>
<output>75</output>

<result>75</result>