The average score of a test in a class is 70 points, and (3/4) of them pass, and their average score is 80 points. Find the average score of those who failed.
某班级一次考试的平均分数是70分，其中(3/4)的人及格，他们的平均分数是80分．求不及格的人的平均分数．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">80 * (3/4)</gadget>
<output>60</output>

<gadget id="calculator">70 - 60</gadget>
<output>10</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">10 / (1/4)</gadget>
<output>40</output>

<result>40</result>