There are 27 red, yellow, and white balls in a box, among which there are 5 fewer red balls than yellow balls, and 4 more white balls than red balls, so how many yellow balls are there?
盒子里有红、黄、白三种颜色的球共27个，其中的红球比黄球少5个，白球比红球多4个，那么黄球有多少个．
<gadget id="calculator">27 - 5 - 4</gadget>
<output>18</output>

<gadget id="calculator">1 + 1 + 1</gadget>
<output>3</output>

<gadget id="calculator">18 / 3</gadget>
<output>6</output>

<gadget id="calculator">6 + 5</gadget>
<output>11</output>

<result>11</result>