Divide the 99 natural numbers from 1 to 99 into 10 groups. It is known that the average numbers of each group in these 10 groups are equal. So what is the average.
将1～99这99个自然数分成10组，已知这10组中每组的平均数都相等．那么，这个平均数是多少．
<gadget id="calculator">4_950 / 99</gadget>
<output>50</output>

<result>50</result>