There are 40 students in class 61 of a certain school. After a math test, they are graded according to their grades: 90-100 is grade A, 80-89 is grade B, 70-79 is grade C, 69 and below 69 are grades D grade. Grade A: 25%; Grade B: 40%; Grade C: 30%; Grade D: 5%; this time, the list is recorded in order of grades from high to low. Some students who write before and after have the same grades, but The order is still counted from the front to the back, and Li Hua wrote it at the 8th place, and Wang Min wrote it at the 35th place. What is the lowest average score of these two students? (Please write down the calculation formula)
某校六1班共有40位同学，在一次数学测验后按成绩分级：90～100分为A级、80～89分为B级、70～79分为C级、69分及69分以下为D级．A级：25%；B级：40%；C级：30%；D级：5%；这次按成绩从高到低的顺序记录名单，有些写在前后的同学的成绩是相同的，但顺序仍然从前往后的顺序来数，而李华写在第8位，王敏写在第35位．那这两位同学的平均分最低是多少分？(请你写出算式计算)
<gadget id="calculator">90 + 70</gadget>
<output>160</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">40 * (1/20)</gadget>
<output>2</output>

<gadget id="calculator">160 / 2</gadget>
<output>80</output>

<result>80</result>