SOLUTION: If I have 51 Questions in a test, how do I figure out how many I can miss so that I at least get an 80%?

Algebra ->  Average -> SOLUTION: If I have 51 Questions in a test, how do I figure out how many I can miss so that I at least get an 80%?      Log On


   

Question 935032: If I have 51 Questions in a test, how do I figure out how many I can miss so that I at least get an 80%?
Found 2 solutions by rfer, TimothyLamb:
Answer by rfer(16322) About Me  (Show Source):
You can put this solution on YOUR website!
51*0.80=41
so you can miss 10

Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
x = number of missed questions
---
(51 - x)/51 * 100 <= 80
51 - x <= 80/100*51
-x <= 80/100*51 - 51
x <= 51 - 80/100*51
x <= 10.2
---
answer:
you can't miss more than 10 questions
---
Free algebra tutoring live chat:
https://sooeet.com/chat.php?gn=algebra
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations with quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php
---