There are three piles of Go pieces, the ratio of the first pile to the other two piles is 1:2, the number of pieces in the second pile is 2/3 of the other two piles, and the third pile has 20 pieces. How many pieces are there in these three piles?
有三堆围棋子，第一堆与另外两堆的比是1：2，第二堆的枚数是另外两堆的(2/3)，第三堆有20枚，这三堆棋子共有多少枚？
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">2 + 3</gadget>
<output>5</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (1/3) - (2/5)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">20 / (4/15)</gadget>
<output>75</output>

<result>75</result>