If your average in the first 7 quizzes is 72% and the passing grade is 75%, What grade should you get in the eight quiz to get a passing average?

2
by acel1234

• Brainly User
2015-12-27T10:45:22+08:00
Average of 7 quizzes:  72%
Grade for 8th quiz:  x %

Equation:

72 + x ≥ 150

72-72 + x ≥ 150 - 72

x ≥ 78

ANSWER:  The student must get at least 78% in the 8th quiz to get a passing average.

Note:  The problem involves inequality because of the word "passing" meaning at least.  Other keywords for inequality may include at least or miminum (≥), the most or maximum (≤)

Modertor/Admin: 96% is correct. Thanks :-)  My equation and solution is are in the comment section.    Rest assured that this is an honest mistake :-)  Have a blessed day :-)
You too. ☺
^ erratum: ...and solution ARE... (not is are).  One way of adding credibility to your answer is deriving an equation. Then using that equation to show how you come up with your final answer:-)  Practice deriving equation from the problem.  If you do, I assure you, Physics, and higher Math will not be difficult.
hmmm.. I'll try.. Thanks for the advice. ☺
Will someone please report my answer as I made mistake, so JoecelE who originally gave the correct answer and was mistakenly reported as incorrect and deleted could re-post post his answer and solution?  Thanks :-)
2015-12-27T20:37:34+08:00
It seems that the other question was accidentally reported and now deleted by a moderator. Also, sorry I'm not that good in deriving algebraic expression but here's my answer.

(72 + x) ÷ 8 ≥ 75
(72 + x) ÷ 8 × 8 ≥ 75 × 8
72 + x ≥ 600
72 + x - 72 ≥ 600 - 72
x ≥ 96

So, you must get a grade 96% (or greater than 96) in order to get a passing average.
So that it will be clear :)
yes, that's the answer deleted. And that's supposed to be my equation and solution.  Thanks.