An exam in a certain class has an average score of 85 points, among which (7/8) pass, and the average score of the passing students is 90 points, so what is the average score of the failing students?
某班一次考试，平均分为85分，其中(7/8)及格，及格的同学平均分为90分，那么不及格的同学平均分是多少分．
<gadget id="calculator">85 * 8</gadget>
<output>680</output>

<gadget id="calculator">90 * 7</gadget>
<output>630</output>

<gadget id="calculator">680 - 630</gadget>
<output>50</output>

<gadget id="calculator">8 - 7</gadget>
<output>1</output>

<gadget id="calculator">50 / 1</gadget>
<output>50</output>

<result>50</result>