Known 3, 5, 7, 9, 11, what is the average of these 5 numbers.
已知3、5、7、9、11，这5个数的平均数是多少．
<gadget id="calculator">3 + 5 + 7 + 9 + 11</gadget>
<output>35</output>

<gadget id="calculator">35 / 5</gadget>
<output>7</output>

<result>7</result>