The sum of the minuend, the subtrahend and the difference is 180, the subtrahend is twice the difference, what is the subtrahend.
被减数、减数与差的和是180，减数是差的2倍，减数是多少．
<gadget id="calculator">1 + 2 + 2 + 1</gadget>
<output>6</output>

<gadget id="calculator">180 / 6</gadget>
<output>30</output>

<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<result>60</result>