# My teacher has failed to teach us this. >.<

• April 12th 2008, 12:15 PM
Fyere
My teacher has failed to teach us this. >.<
Okay, I have a few problems given to me by my teacher due Monday. Most of it was review of what we've already done, but the last 3 questions I don't remember ever learning. We did something similar, but no identical questions to this.

For this one, I asked my friend for help but he told me it must have been a typo or something, cause it can't be done. I'll just post it anyway.

1) How many days will it take for $1 000 000 to earn$1643.84 interest at 12%/a?

2) What volume of material with density 4.2g/cm ^3 has a mass of 1.8 kg? Answer to the nearest 0.1 cm^3.

I was thinking it was the V=D/T equation, but I don't kow what the t would equal. The 1.8 kg? But I thought t= time. So basically I'm confused.

3) How many metres would you travel in 22 min at 48 km/h?

Help would be much appreciated! =D
• April 12th 2008, 12:18 PM
Mathstud28
Quote:

Originally Posted by Fyere
Okay, I have a few problems given to me by my teacher due Monday. Most of it was review of what we've already done, but the last 3 questions I don't remember ever learning. We did something similar, but no identical questions to this.

For this one, I asked my friend for help but he told me it must have been a typo or something, cause it can't be done. I'll just post it anyway.

1) How many days will it take for $1 000 000 to earn$1643.84 interest at 12%/a?

2) What volume of material with density 4.2g/cm ^3 has a mass of 1.8 kg? Answer to the nearest 0.1 cm^3.

I was thinking it was the V=D/T equation, but I don't kow what the t would equal. The 1.8 kg? But I thought t= time. So basically I'm confused.

3) How many metres would you travel in 22 min at 48 km/h?

Help would be much appreciated! =D

the last two are unit conversion...sort of you know that $D=\frac{m}{v}$ and using google to convert like put 48 kilometers to miles and it will give you the conversion
• April 12th 2008, 02:45 PM
mr fantastic
Quote:

Originally Posted by Fyere
Okay, I have a few problems given to me by my teacher due Monday. Most of it was review of what we've already done, but the last 3 questions I don't remember ever learning. We did something similar, but no identical questions to this.

For this one, I asked my friend for help but he told me it must have been a typo or something, cause it can't be done. I'll just post it anyway.
[snip]

This is off-topic but I believe the title of this thread

( My teacher has failed to teach us this. >.< )

deserves a response:

It's a common MISconception among students that unless the teacher shows them how to do every possible example for a particular topic, then the teacher hasn't taught them.

In fact, once you've been shown the theory and given some examples, it's very reasonable to be given questions that are not identical to the examples. It's expected that you can apply your understanding, not just be a trained parrot and reproduce solutions using a standard template. Not to mention the fact that to cover every conceivable example for a given topic could take years ....

"We did something similar, but no identical questions to this." And there we have it - the root of the trouble. The ineptitude of the teacher is exposed.

Many a student has cursed the fact that an exam they sat was not the same as the one from the previous year. How unfair, they say. We were never taught this. We never learned this. Yada yada. What they're really saying is that it's unfair that they memorised how to do the questions from the previous year and were cheated by getting questions that they hadn't memorised how to do. Perish the though that the examination should be exactly that, an examination (of understanding).

Stop blaming your teacher for not teaching you the work and get on with the business of understanding how to apply what you've been taught.
• April 12th 2008, 06:24 PM
Fyere
I understand what I have been taught. But the way the question is phrased just doesn't make sense to me. I read my notes over, I ha been attempting to figure out the question based on material I already understand, and I still didn't get it. I'm not just some kid who doesn't understand something, then demands for help. So maybe I rephrased my topic wrong. Maybe I should have said "I'm stupid and cannot contemplate something my teacher has touched base on before". I was frustrated at the time and couldn't think of a title.

While I appreciate your response, the lecture was completely unneeded. That went on for a good few paragraphs which I found ridiculous. A mere statement would have been fine. The way you responded felt more like I had hit a pet peeve of yours.

Anyway, I've figured it out.

And for the record, this place is supposed to be a forum for encouragement of students who struggle with Math. I just signed up today, and I highly doubt I'll be posting again.

Thanks for whoever helped me out. ^^
• April 12th 2008, 07:36 PM
mr fantastic
Quote:

Originally Posted by Fyere
I understand what I have been taught. But the way the question is phrased just doesn't make sense to me. I read my notes over, I ha been attempting to figure out the question based on material I already understand, and I still didn't get it. I'm not just some kid who doesn't understand something, then demands for help. So maybe I rephrased my topic wrong. Maybe I should have said "I'm stupid and cannot contemplate something my teacher has touched base on before". I was frustrated at the time and couldn't think of a title.

While I appreciate your response, the lecture was completely unneeded. That went on for a good few paragraphs which I found ridiculous. A mere statement would have been fine. The way you responded felt more like I had hit a pet peeve of yours.

Anyway, I've figured it out.

And for the record, this place is supposed to be a forum for encouragement of students who struggle with Math. I just signed up today, and I highly doubt I'll be posting again.

Thanks for whoever helped me out. ^^

1. "Maybe I should have said "I'm stupid and cannot contemplate something my teacher has touched base on before". I was frustrated at the time and couldn't think of a title."

A simple 'Help needed' would have sufficed. Titles that are professionally insulting are not acceptable, in my opinion. Unless directed towards lawyers, of course.

2. "While I appreciate your response, the lecture was completely unneeded. That went on for a good few paragraphs which I found ridiculous. A mere statement would have been fine."

Perhaps.

3. "The way you responded felt more like I had hit a pet peeve of yours."

Yes it is. And the way you've responded suggests likewise. In these current times it's all too easy to blame others for one's own difficulties. Teachers present a particularly large target in this respect.

4. "And for the record, this place is supposed to be a forum for encouragement of students who struggle with Math. I just signed up today, and I highly doubt I'll be posting again."

That's your choice. Your threats and comments are inappropriate, in my opinion. If I am sanctioned as a result of your response (as it most likely intended), so be it. I stand by my comments.

• April 13th 2008, 03:08 AM
janvdl
Quote:

Originally Posted by mr fantastic
1. "Maybe I should have said "I'm stupid and cannot contemplate something my teacher has touched base on before". I was frustrated at the time and couldn't think of a title."

A simple 'Help needed' would have sufficed. Titles that are professionally insulting are not acceptable, in my opinion. Unless directed towards lawyers, of course.

2. "While I appreciate your response, the lecture was completely unneeded. That went on for a good few paragraphs which I found ridiculous. A mere statement would have been fine."

Perhaps.

3. "The way you responded felt more like I had hit a pet peeve of yours."

Yes it is. And the way you've responded suggests likewise. In these current times it's all too easy to blame others for one's own difficulties. Teachers present a particularly large target in this respect.

4. "And for the record, this place is supposed to be a forum for encouragement of students who struggle with Math. I just signed up today, and I highly doubt I'll be posting again."

That's your choice. Your threats and comments are inappropriate, in my opinion. If I am sanctioned as a result of your response (as it most likely intended), so be it. I stand by my comments.

You can really be harsh on them sometimes, Mr F. (Rofl)

(Not undeservingly harsh though.) (Yes)
• April 13th 2008, 03:20 AM
janvdl
Quote:

Originally Posted by Fyere
1) How many days will it take for $1 000 000 to earn$1643.84 interest at 12%/a?

(At last I can test out my new financial calculator! :D)

Recall the compound interest formula.

$A = P(1 + \frac{i}{100})^n$

$1 001 643,84 = 1 000 000(1,12)^n$

$\frac{1001643,84}{1000000} = (1,12)^n$

$n = \log _{1,12} \frac{1001643,84}{1000000}$

$n = 0,0145$ Years

$n = 5,29$ days.
• April 13th 2008, 03:35 AM
cokhale
1. simple interest = prt\100

t = 1643.84* 100/1000000
= 16/100 = 8/50 = 4/25.
• April 13th 2008, 06:21 AM
CaptainBlack
Quote:

Originally Posted by cokhale
1. simple interest = prt\100

t = 1643.84* 100/1000000
= 16/100 = 8/50 = 4/25.

The trouble is that when the helpers see this type of question their (our?) first thought is continuouly componded interest, however the context provided by the other questions makes it unlikely that that is the intended meaning.

(P.S. where has the interest rate gone, and units of time - days asked for looks like about 5 days to me)

RonL
• April 13th 2008, 08:56 AM
cokhale
t = simple interest* 100/p*r

t = 1643.84* 100/1000000* 12 = 1.9 =2 days
• April 13th 2008, 09:30 AM
CaptainBlack
Quote:

Originally Posted by cokhale
t = simple interest* 100/p*r

t = 1643.84* 100/1000000* 12 = 1.9 =2 days

and how many days in a year are there, and where does it appear in this?