Question 290657
according to your category choice this problem is about unit conversion.
Which units are being converted?

There are several approaches to this problem.
For the student to get 80 average he must get at least 80 on the next test plus make up for all the marks less than 80.
here are hos overages and underages:

+2-7+0-4+4

so he is under 5
so he needs at least 85

(395+x)/6=80
x=85