Mathematical Question

[Saturos]

OK, heres the situation: I have a math exam tomorrow. It is worth 30% of my whole year. I am getting 55% in the course. My question is this: What is the minimum percentage mark that I can get on the exam and still pass the course(50%)?

[spockman]

I could be totally wrong, as I just did some stuff that seemed right, but I figure... 44%

[Saturos]

Thank you, now I don't have to study that hard lol.

[reci]

You need to get 38 and (1/3)% on the exam to have a 50% average.

[Xei]

38% is correct. Perhaps you should revise percentages...

[Spartiate]

Is this a final exam? At my school, you had to pass the final (government) exam regardless of your total percentage for the year, so you might not be out of the woods yet .

[Phion]

It's kind of a vague question and there are many ways to calculate grade averages.

[Saturos]

No, I'm pretty sure you don't have to pass the exam, just the course. Also, percentages aren't on the test, thankfully.

[Phion]

Yea, from what he gave us I figure he only needs to score like a 16% on the test to maintain a 50% average. [50% ≤ 55% + .3*x]

[Xei]

.7*55% surely.

[Phion]

.7*55% surely. Aye, one would think... but from the information presented, he'd actually need to score negatively (not possible?) to drop his average percentage down to 50%.

[Marvo]

I don't understand the question, maybe because I'm not familiar with the school system you're using. Anybody who can rewrite it?

[Xei]

He has to get 50% of the answers right. In the tests so far, which constitute 70% of the total questions, he's scored 55%. 30% of the total number of questions remain. What percentage of right answers does he need? Aye, one would think... but from the information presented, he'd actually need to score negatively (not possible?) to drop his average percentage down to 50%. No... if he got 55% in the remaining exams he'd average 55%. If he didn't try at all clearly this would cause his average grade to drop, because the number of questions asked has increased but the number answered correctly has remained the same.

[Marvo]

Yeah I'm getting 38,5% of the entirety of questions asked so far have been answered correctly, which means that of the remaining 30% of questions, he has to answer 38,333333...% correctly. Am I right?

[DuB]

I hope this isn't a college exam you're about to take. Because this question is very, very, very basic algebra.

[Xei]

Yeah I'm getting 38,5% of the entirety of questions asked so far have been answered correctly, which means that of the remaining 30% of questions, he has to answer 38,333333...% correctly. Am I right? Except for your absurd European decimal points, yes. To be honest I might start using them. It's currently quite confusing when your multiplication signs are virtually identical to your decimal point signs. Oh and 8 significant figures was probably a bit excessive, his exams are unlikely to have more than 100,000,000 questions. I'll stop being a jerk now.

[DuB]

Yeah I'm getting 38,5% of the entirety of questions asked so far have been answered correctly Technically it's 38.5% of the entirety of questions--including the ones that haven't been asked yet. As his current grade indicates, he's answered 55% of the questions asked up until this point correctly. But yeah, the numbers are right.

[Marvo]

Technically it's 38.5% of the entirety of questions--including the ones that haven't been asked yet. As his current grade indicates, he's answered 55% of the questions asked up until this point correctly. But yeah, the numbers are right. Oh yeah, that's what I meant, just wrote something else Xei, most of the software I use in school actually uses . for decimal stuff, like Graph and MathCad. As far as I know, it's mostly just danes that still use , for decimals.

[Xei]

Nah, it's the whole of Europe except the UK pretty much. I've had a few foreign tutors who haven't kicked the insidious habit.

[Replicon]

Two comments: 1) If you can't figure out the answer to your question yourself, then it's likely you'll just fail the friggin math test altogether 2) While the final might be worth X marks, be careful: Some marking schemes have a proviso that you MUST pass the final to pass the course, so don't set your sights really low. I used to calculate how I need to do on a final sometimes in university, but mainly so that I don't feel stressed (hey as long as I get over 30% on the final I pass so no problem! no stress!) and then I do better than if I were freaking out. Also, when I had to choose between two finals to study more for, I knew where to focus my energy

[spockman]

Oh, okay. I didn't calculate for a weighted grade.

[Phion]

OK, heres the situation: I have a math exam tomorrow. It is worth 30% of my whole year. I am getting 55% in the course. My question is this: What is the minimum percentage mark that I can get on the exam and still pass the course(50%)? I interpret thusly: Assuming the teacher isn't using a simplified grading system, the test is worth 30% of the entire quarters average, and included in the 55% are homework, quizzes, papers - basically everything except for the final. After taking a simple sum of test grades and scores, then averaging over a specified number, one would usually then multiply each category by some factor (ie. homework is worth 10% of the average, quizzes are worth 20%, et cetera). So, for example, say you get a simple average of 80% on a quiz, but it's worth 20% of the quarters grade, you would then multiply 80% by .2 (16%) and repeat similarly for the other categories. Next you would then add all of the new averages to get the actual weighted average for the entire quarter. Now what the OP wants to know is what would he need to score on a test that's worth 30% of the entire quarters average? Well, one would have to set the sighted averaged to attain (50%, at least) equal to the sum of the weighted averages (50 = 55 + .3*x), x being required score needed to attain at least a 50%. Although, perhaps I've misinterpreted the question entirely. There are as many ways to calculate grade averages as there are teachers.

[DuB]

You left out a term. You didn't weight the current 55% grade. .7(55) + .3(x) = 50

[Phion]

Haha - I've taken up to Calc III and this is what I have to show for it.

[kookyinc]

I got 38.3333...% as well. G'luck. Unrelated: I love math.