There are several natural numbers, if the largest number is removed, the average of the remaining numbers is 8; if the smallest number is removed, the average of the remaining numbers is 10. It is known that the largest number is 20 greater than the smallest number, how many numbers are there in this group of natural numbers?
有若干个自然数，如果去掉最大的数，则余下的数的平均数是8；如果去掉最小的数，则余下的数的平均数是10．已知最大的数比最小的数大20，则这组自然数有多少个数．
<gadget id="calculator">22 / 2</gadget>
<output>11</output>

<result>11</result>