Math people, please help me understand this

Okay, so I was working on my practice test for math a minute ago, and on the first attempt I got a problem wrong and can not figure out what was going on with it.

The question is:
A manufacturer has a monthly fixed cost of $70,000.00 and a production cost of $17 for each unit produced. The product sells for $26 per unit. Find the break-even revenue.
a)
b)
c)
d)
e)
f) None of the above.


I got the answer wrong by picking F, and after taking the second test again later, the question was slightly changed and I got it right, but I don't understand why it's wrong. I understand if it was asking for the break-even quantity, but none of those are break-even revenue. There was the exact same question before in an earlier quiz:

A manufacturer has a monthly fixed cost of $70,000 and a production cost of $17 for each unit produced. The product sells for $26 per unit. Find the break-even revenue.
a) $3,684.21
b) $202,222.22
c) $2,692.31
d) $7,777.78
e) $1,627.91
f) None of the above.

So i'm thinking that there was a typo in the practice test, because the answer would be $202,222.22, which is in the quiz answers. Or am I going crazy on this?

 

But then x would stand for a number of units, not a revenue. They asked for a revenue. 0/10 garrulous.

Are all your math tests standardized tests in the US or what ? You have to explain how you got your answer here. If you made a calculus mistake along the way but had the correct reasoning you still get half the points. If you somehow got to the right answer with a flawed reasoning you get nothing.

 

That is how most of tests are done, but we do have A LOT of standardized tests.

Anyway, for this problem you need to take the break even quantity and then find the revenue from that quantity. As noted above the quantity is 70,000/9. You can use either side of the equation but I would just use the 26x giving you 1820000/9, Which is A.

 

Not very useful step-wise is that? Better to go

26x = 17x + 70000

26x - 17x = 9x

9x = 70000

divide by nine and you get 70000/9, but that's just quantity, not revenue. The revenue is R(x), being 26(70000/9). Now the issue I had looking at it was how the heck do you get the answer out of that, but I managed to remember how the flying-fluck you get it after doing the second test by checking my math with the other answers. I was forgetting that looking at it 26 is also 9 over 9, just 26 times, so you could multiply 70000 by 26 and get the answer. Trying to get the Break-Even point in the second practice test I understood where the fractions came from, but I feel silly having trouble, especially since 1820000/9 is 202222.222, which is the same answer as the question from the quiz.

And here I thought there was a typo. Also, I just realized that even though I got the question earlier, trying to explain you tiny post in steps made it easier to understand........how the fluck does that work?

Isn't that a little harsh saying they have the IQ level of a dog?

And don't look at me, I was good with a simple math class in Colorado, but UH makes me take 2 extra math classes. Also, not everyone can do everything in their head. I can do most math in my head and make it easier, but I was listening to music to make it less boring, so meh. Good thing it was a practice test only

 

@Incognitus, can I ask you for help when I need it? :D

 

What am I, chopped-liver? Just because I have brain-flops a few times doesn't mean I can't do math

 

Most people structure information in their head differently for themselves and for explaining it to others. Usually the thought structure for yourself is faster but less organized and thus more error prone. Because of this it helps when stuck on a problem, or trying to hold on to information longer, to pretend that you are explaining it to someone else instead.

 

That or your brain went on vacation to Hawaii and doesn't wish to send you that information you want to remember. Most of the time I get stuck on a problem it's because I just completely forget it, but usually I'll remember all the terms and formulas to use, just get them mixed up because of my teensy handwriting. Earlier today during my first practice test I got a matrix problem wrong with the Gauss-Jordan method because I missed a negative symbol......I always go so fast at math because it's easy that I miss things something, and when I slow down to look at it I wonder "what the heck do I do?".

What I need is someone to teach me how to sleep while doing schoolwork, than my mind can be on one thing: sleep. Don't look at the logic of that, there was none to begin with

 

Okay, smart guy. I solved this question for my homework. Can you?

 

You know what annoys me? This is one of those things I know I learned at one point, very briefly, and I can be certain of that, and yet I can not answer it because I haven't done it in who-knows-how-long. It's like when I first looked at Matrices this semester. I remember them being easy, but I couldn't remember how to do them right away. Am I at least correct it's one of those A/B=C/D problems? Wish I could write that, but no pen on this forum

edit: okay, took a random stab at it, and I seriously doubt it's right, in any sense of the word, whether you're looking for a decimal, fraction, or just a right answer in general, but taking a stab at what I thought was right I got X=.625 or x=5/8

 

I assumed it was beneath you, yeah. Hell it' s beneath me.
I wouldn' t spend more than a line on that one either, but then the answers expected of me were a tad bit lengthier.
I had a good laugh when I compared my finals exam with that of our literary students, I swear one of their questions was "what are your odds to get a 6 with a 6-faced dice ?"

 

My high school geometry and Algebra II teacher, same person if that isn't clear, wanted to see our math problems on paper all the time, so it was annoying when I knew I could do it in my head in 3 seconds compared to wasting time writing.

Also, keep that question in mind and I'll answer it later, soon as we learn probability

 

Nested fractions are needlessly tedious IMO. You can collapse that one down to 5/4x = 4. That is of course assuming my reading it as "(5/4)/x = 0.75/(3/8)" was correct

 

So far as my memory is concerned the gauss-jordan method is needlessly tedious out of all the math I know. And yeah, I was reading it as (5/4)/x=.75/(3/8) too. And I might have made it more difficult, but I just switched it to
.75x = 15/32 and made 15/32 a decimal with the calculator. I'm sure there was an easier way as I was checking my answer online, but I don't remember the method, so meh.

 

@Iskandar, 5/8 is correct.

Now, @Iskandar, @Incognitus, @Mixt, maybe you guys can help me, because I am absolutely frustrated. We started word problems today, which are hell, and there are only two that I can't answer in what was assigned for homework out of the nine total, which isn't bad, but for many of them, I also had to waste time re-arranging the numbers, eventually getting the correct answer, but it doesn't help if I don't know why.

The thing about word problems is that you have to put the numbers in the correct places yourself and they have to match. Hours / Miles = Hours / Miles would be correct while Hours / Miles = Miles / Hours would be incorrect, the former of which is getting me.

For example:

If I do x/75 = 6/325 (325x = 75 * 6), I get an incorrect answer of 1.38 minutes; however, if I do x/325 = 6/75 (75x = 325 * 6), I get a correct answer of 26 minutes. But why!? I already have both numbers on the bottom matching (both are the number of pushups), so why does 325 have to be on the bottom-left and 75 on the bottom-right in fraction form? (Or, in other words, why does the X have to be with 75 instead of 325?)

 

Grouping matters. In your first set up you are solving for x minutes to do 75 pushups if it takes 6 minutes to do 325 pushups. Of course it give a different answer, because you are answering a different question.

Think of it like you are drawing the connections to make a square. You are connecting the units fine but you need to connect the source of those numbers as well.