There are 5 bags of balls, a total of 850 balls. Each bag contains two kinds of balls, black and white, and the number of each ball is the same. How many white balls are there on average in each bag?
有5袋球一共850个每袋里有黑、白两种，每种球的个数同样多．平均每袋里有白球多少个？
<gadget id="calculator">850 / 5 / 2</gadget>
<output>85</output>

<result>85</result>