A, B, and C have 3 identical cups. The average height of the two cups of water in A and B is 11 cm, the average height of the two cups of water in B and C is 12 cm, and the average height of the two cups of water in A and C is 7 cm. What is the average height of the three glasses of water in centimeters?
A、B、C3只相同的杯子，A、B两杯水的平均高度是11厘米，B、C两杯水的平均高度是12厘米，A、C两杯水的平均高度是7厘米．这三杯水的平均高度是多少厘米？
<gadget id="calculator">2 * 11</gadget>
<output>22</output>

<gadget id="calculator">2 * 12</gadget>
<output>24</output>

<gadget id="calculator">2 * 7</gadget>
<output>14</output>

<gadget id="calculator">22 + 24 + 14</gadget>
<output>60</output>

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

<gadget id="calculator">30 / 3</gadget>
<output>10</output>

<result>10</result>