There are four numbers, choose three of them each time, calculate their average, and add another number. Using this method to calculate 4 times, get four numbers respectively: 26, 32, 40, 46, then what is the average of the original four numbers.
有四个数，每次选取其中三个数，算出它们的平均数，再加上另外的一个数．用这样的方法计算了4次，分别得到四个数：26，32，40，46，那么原来四个数的平均数是多少．
<gadget id="calculator">26 + 32 + 40 + 46</gadget>
<output>144</output>

<gadget id="calculator">144 / 2 / 4</gadget>
<output>18</output>

<result>18</result>