The sum of the minuend, the subtrahend and the difference is 100, and the subtrahend is 10 greater than the difference. What is the difference?
被减数、减数与差的和是100，减数比差大10，差是多少．
<gadget id="calculator">100 / 2</gadget>
<output>50</output>

<gadget id="calculator">50 - 10</gadget>
<output>40</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<result>20</result>