SOLUTION: if i have a 81 in a class and my exam is worth 20% what do i need to make to keep my 80

Question 541843: if i have a 81 in a class and my exam is worth 20% what do i need to make to keep my 80
Found 2 solutions by Alan3354, solver91311:
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
if i have a 81 in a class and my exam is worth 20% what do i need to make to keep my 80
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You wanna keep 81? Or 80?
The 81% is the average of 80%, or 4/5 of the grade
Anyway, (81*4 + score)/5 = 80
324 + score = 400
score = 76% to average 80% overall
76%
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To maintain 81%, you have to make 81%

Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!

This is a weighted average problem. If 20% of your grade is the exam, then the 81 average you have already must be 80% of your grade. You don't know the grade you are going to get on your exam, so let represent that number:

Just solve for

John

My calculator said it, I believe it, that settles it

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