NationStates Jolt Archive

Just wondering how observant and maths-savvy you lot are; only three questions at the moment but I'll post more later.
Apologies for the content; I'm tired and can't think of anything better.

1. If person A earns £1.00 and person B earns £0.75, how much more (as a percentage) does person A earn?

2. How much less does person B earn as a percentage?

3. 6 x 7 x 378 x 2 x 97.5 x 1973 x 56 x 72.835 x 819 x 58 x 2 x 19 x 56821 x 956 x (4-2^2) x 19.627 x 57 + (15) x (82-3^4) - (16) + 1 = ?


Put your answers in white text or something, please, so that other people can answer as well.

The answers are in white text below.

1. 33.3...%
100 - 75 = 25
75 / 25 = 3
100 / 3 = 33.3...

2. 25%
100 - 75 = 25
100 / 25 = 4
100 / 4 = 25

3. 0
6 x 7 x ... x (4-2^2) [This equals 0; when we multiply a number by 0, we get 0. Therefore the answer is 0 at this point.] ... + (15) x (82-3^4) [We've been multiplying 0 up until this point, yielding 0 each time; however, here, we're adding 15 and multiplying by 1, yielding 15.] ... -(16) [15 - 16 = -1] + 1 = 0
Voila!

Why did you have to be observant?
To spot the key words in questions 1 and 2 and the key numbers and operations in question 3.

1: 33% more
2: 25% less
3: 0

*yawn*

1: 33% more
2: 25% less
3: 1

*yawn*

Unless I made a mistake 3 should be 0.
And I know it's simple. Forgive me. I'm tired. :(

Give us some algebra!

Give us some algebra!

Algebra very rarely requires you to be observant in my experience.
I suppose I could give you some of the complicated equations I made to get simple answers and ask you to figure out what the result is...

Unless I made a mistake 3 should be 0.
And I know it's simple. Forgive me. I'm tired. :(

I looked it over again and corrected it.

I'm not observant. I read 82 as 81, so I would get 0 for this part.... Not sure why reading the first questions would make anyone observant, though.

I looked it over again and corrected it.

*wipes his brow*
Phew. I'm not used to making mistakes when it comes to mathematics. :D
Apart from when doing integral calculus, but that's because I'm only 15... or... something...
I mean... at least I can do it 50% of the time... :(

I'm not observant. I read 82 as 81, so I would get 0 for this part.... Not sure why reading the first questions would make anyone observant, though.

Because they'd have to notice the 'more' and 'less' and realise the difference.

*wipes his brow*
Phew. I'm not used to making mistakes when it comes to mathematics. :D
Apart from when doing integral calculus, but that's because I'm only 15... or... something...
I mean... at least I can do it 50% of the time... :(

Give us some calculus then, I need to revise for maths!

oh and isn't 15 a year early if you want to do calculus, unless you are doing extra classes

Because they'd have to notice the 'more' and 'less' and realise the difference.

I call this plain reading :P

Give us some calculus then, I need to revise for maths!

Integrate this: e^(x^2) :)

bleh, i'm 22 and i just had to get my dad to explain percentages to me. there's no way i'm going to attempt something with that many numbers, functions and symbols in it.

Give us some calculus then, I need to revise for maths!

oh and isn't 15 a year early if you want to do calculus, unless you are doing extra classes

What's the derivative of (x-4)^4 (ln|sqrt(x-3)|/(x^2-x+76)?

Give us some calculus then, I need to revise for maths!

oh and isn't 15 a year early if you want to do calculus, unless you are doing extra classes

I am taking extra classes. During my lunchtimes.
Needless to say, I tend to eat very little at school nowadays.

Differentiate this: 6x^4 + 2x^3 + 4.

I call this plain reading :P



Integrate this: e^(x^2) :)

Well, I know many people who wouldn't distinguish between the 'more' and 'less'.
And in regards to your equation: oh, you are just plain evil. :D

bleh, i'm 22 and i just had to get my dad to explain percentages to me. there's no way i'm going to attempt something with that many numbers, functions and symbols in it.

But... but... those're the most simple things I can come up with off the top of my head...

What's the derivative of (x-4)^4 (ln|sqrt(x-3)|/(x^2-x+76)?

Integrate this: e^(x^2) :)

On second thoughts, i'm to tired for this shit right now :p

But... but... those're the most simple things I can come up with off the top of my head...

heh, adding and subtracting is about all my brain can deal with when it comes to maths these days. i used to be pretty good at maths til i was about 15 then i just lost it.

On second thoughts, i'm to tired for this shit right now :p

I'll give you a hint: use logarithms to break it up into simpler pieces.

I suck at teh maths. I got #2 right, and didn't even attempt three.

I am taking extra classes. During my lunchtimes.
Needless to say, I tend to eat very little at school nowadays.

Differentiate this: 6x^4 + 2x^3 + 4.

24x^3 + 6x^2

I could do that in my sleep :p. Wait til you start diff eq.

What's the derivative of (x-4)^4 (ln|sqrt(x-3)|/(x^2-x+76)?

Ok, here goes nothing

(4(x-4)^3(ln((x-3)^(.5))/(x^2-x+76))+(((x-4)^4(((x^2-x+76)(.5((x-3)^(-.5))/((x-3)^(.5)))-((2x-1)ln((x-3)^(.5))))/((x^2-x+76)^2)))

I hope I did not forget a parenthesis.
This is really hard to type in. You know?:)

Ok, here goes nothing

(4(x-4)^3(ln((x-3)^(.5))/(x^2-x+76))+(((x-4)^4(((x^2-x+76)(.5((x-3)^(-.5))/((x-3)^(.5)))-((2x-1)ln((x-3)^(.5))))/((x^2-x+76)^2)))

I hope I did not forget a parenthesis.
This is really hard to type in. You know?:)

I, um, never bothered to do it.

I was thinking about doing it tomorrow in TeX to make it look remotely readable.

I, um, never bothered to do it.

I was thinking about doing it tomorrow in TeX to make it look remotely readable.

I got really bored.

What else is a seventeen year old, high school senior going to do in his free time?

1. If person A earns £1.00 and person B earns £0.75, how much more (as a percentage) does person A earn?
2. How much less does person B earn as a percentage?


A earns 33% of B's wage more than B, or, if you prefer, A's wage is 25% of his own wage greater than B's wage.
This means that B earns 25% of A's wage less than A, or 33% of his own wage less than A.Percentages are relative.


3. 6 x 7 x 378 x 2 x 97.5 x 1973 x 56 x 72.835 x 819 x 58 x 2 x 19 x 56821 x 956 x (4-2^2) x 19.627 x 57 + (15) x (82-3^4) - (16) + 1 = ?

4-2^2=0. 15-16+1=0. Total 0.

I call this plain reading :P



Integrate this: e^(x^2) :)

Gaussian integral. 1/2*sqrt(pi)*Erfi(x) . Erfi is the imaginary error function.

A earns 33% of B's wage more than B, or, if you prefer, A's wage is 25% of his own wage greater than B's wage.
This means that B earns 25% of A's wage less than A, or 33% of his own wage less than A.
Percentages are relative.


4-2^2=0. 15-16+1=0. Total 0.

Don't ruin it for us or anything :p

My contribution:
1/0=?
OH SH-

What's the derivative of (x-4)^4 (ln|sqrt(x-3)|/(x^2-x+76)?

I think you mean: (x-4)^4 * ln ( |sqrt(x-3)|/(x^2-x+76) ) .

assuming x real, domain is x>3 (because of the square root and the ln).

4(x-4)^3 * ln ( |sqrt(x-3)|/(x^2-x+76) ) + (x-4)^4 * ( |sqrt(x-3)|/(x^2-x+76) ) ^ (-1) * ( 1/(2*sqrt(x-3)) * (x^2-x+76) - sqrt(x-3) * (2x-1) ) * (x^2-x+76)^(-2) .

:)

1. If person A earns £1.00 and person B earns £0.75, how much more (as a percentage) does person A earn?

2. How much less does person B earn as a percentage?These questions are unanswerable (in the strictest sense), as you do ask state much person A or B earns in comparison to whom.

That is to say. A earns 33% more than B, but A also earns 0% more than A.
When phrasing a maths question you should be very explicit - nothing should ever be implied.

eg. As a percentage of person A's income, how much more than person B does person A earn?

These questions are unanswerable (in the strictest sense), as you do ask state much person A or B earns in comparison to whom.
I'm sure the bolded part might make sense to someone...

I think you mean: (x-4)^4 * ln ( |sqrt(x-3)|/(x^2-x+76) ) .

assuming x real, domain is x>3 (because of the square root and the ln).

4(x-4)^3 * ln ( |sqrt(x-3)|/(x^2-x+76) ) + (x-4)^4 * ( |sqrt(x-3)|/(x^2-x+76) ) ^ (-1) * ( 1/(2*sqrt(x-3)) * (x^2-x+76) - sqrt(x-3) * (2x-1) ) * (x^2-x+76)^(-2) .
Yes.

What.
The.
Fuck?

Don't ruin it for us or anything :p


Sorry. Edited it, in white now.

A bit of geometry.

I am on point A on Earth's surface (let's assume it perfectly spherical).
I walk 1 km south. Then I walk 1 km east. Then I walk 1 km north. I find that I am now back at point A.

Where is point A?

Of course, the simplest (trivial) solution is: point A is the North Pole.

But there is also an infinite set of other points that are solutions to this problem. Can you find them?



There is a parallel, that is exactly at 1+1/(2*pi) kilometers north of the South Pole. Its points are ALL solution to the problem. You start going south for 1 km; then you circle the pole on a circle whose circumference is exactly 1 km, then you go back north.

There are also infinite circles around the South Pole: assume k a natural number greater than 0, then the parallel at 1+1/(2*pi*k) km north of the South Pole is an infinite set of solutions! You make k circles around the pole.

The parallel at exactly 1 km north of the South Pole isn't a set of solutions, because you can't walk 1 km east by standing exactly on the South Pole. From the S.P you can move only north. You'd be rotating on yourself, but you'd travel no distance.



:D

Somone said differentiate(dire spelling on my part) this:
f(x)=6x^4 + 2x^3 + 4
well:
f'(x)=24x^3+6x^2+0

I think you mean: (x-4)^4 * ln ( |sqrt(x-3)|/(x^2-x+76) ) .

assuming x real, domain is x>3 (because of the square root and the ln).

4(x-4)^3 * ln ( |sqrt(x-3)|/(x^2-x+76) ) + (x-4)^4 * ( |sqrt(x-3)|/(x^2-x+76) ) ^ (-1) * ( 1/(2*sqrt(x-3)) * (x^2-x+76) - sqrt(x-3) * (2x-1) ) * (x^2-x+76)^(-2) .

:)for ln ( |sqrt(x-3)|/(x^2-x+76) )

If x=-1

then ln ( |sqrt(x-3)|/(x^2-x+76) ) = -3.69... + 1.57... i


What is pointless is finding the modulus of a square root as a square root of any number is never a -tive. Perhaps he meant SQRT(|x-3|). And x =/= 3.

for ln ( |sqrt(x-3)|/(x^2-x+76) )

If x=-1

then ln ( |sqrt(x-3)|/(x^2-x+76) ) = -3.69... + 1.57... i


What is pointless is finding the modulus of a square root as a square root of any number is never a -tive. Perhaps he meant SQRT(|x-3|). And x =/= 3.

Yeah, that could be.

Somone said differentiate(dire spelling on my part) this:
f(x)=6x^4 + 2x^3 + 4
well:
f'(x)=24x^3+6x^2+0

Quite correct.
And you spelled it correctly.

*snipped in the name of Her Majesty the Queen*

If there's one aspect of mathematics that I'm really weak at then it's geometry...

These questions are unanswerable (in the strictest sense), as you do ask state much person A or B earns in comparison to whom.

That is to say. A earns 33% more than B, but A also earns 0% more than A.
When phrasing a maths question you should be very explicit - nothing should ever be implied.

eg. As a percentage of person A's income, how much more than person B does person A earn?

Alright, so I made a mistake in phrasing the question. I don't write exam papers for a living. Forgive me. I'm a social outcast. And so on and so forth.

Don't ruin it for us or anything :p

My contribution:
1/0=?
OH SH-

ARGH!
Illegal operation!
You shall now be arrested by the mathematics police.

24x^3 + 6x^2

I could do that in my sleep :p. Wait til you start diff eq.

Well, it was intended for Hydesland, O high and mighty mathematician... :D

I suck at teh maths. I got #2 right, and didn't even attempt three.

Despite the fact that 3 was possibly the easiest providing you read the entire thing before attempting to work anything out.
Unless, of course, you use a calculator, in which case I hold no sympathy for you.
(Although I will admit they come in useful for calculating infinite series; arctangents, for example.)

heh, adding and subtracting is about all my brain can deal with when it comes to maths these days. i used to be pretty good at maths til i was about 15 then i just lost it.

Shame.
Mathematics is the greatest pursuit a man can undertake, and it's also the only thing in which one can actually prove something.

Alright, so I made a mistake in phrasing the question. I don't write exam papers for a living. Forgive me. I'm a social outcast. And so on and so forth.So why aren't you writing exam papers? I mean you have admitted to being a social outcast and all.

So why aren't you writing exam papers? I mean you have admitted to being a social outcast and all.

I'm busy programming computer games and making inelegant equations to get simple things like n^x.
That's why. :)

:confused: :confused: :(

:confused: :confused: :(

?

Original Post


C'mon, really, how stupid you think people here are. These are questions for approximately 5th grade. In which grade there was multiplying and decimals. IIRC, 5th grade.

I would assume that even lowest 10% of age (or education level) of NSG is higher than that.

C'mon, really, how stupid you think people here are. These are questions for approximately 5th grade. In which grade there was multiplying and decimals. IIRC, 5th grade.

I would assume that even lowest 10% of age (or education level) of NSG is higher than that.

I did say they were simple.
It wasn't to test peoples' mathematics skills; merely to see whether they'd notice things like the multiplication by 0 and the 'more' and 'less'.

for ln ( |sqrt(x-3)|/(x^2-x+76) )

If x=-1

then ln ( |sqrt(x-3)|/(x^2-x+76) ) = -3.69... + 1.57... i


What is pointless is finding the modulus of a square root as a square root of any number is never a -tive. Perhaps he meant SQRT(|x-3|). And x =/= 3.

The square root of a number is both positive and negative. 3*3 = 9 and -3*-3 = 9. You have to include both as they both satisfy the condition.

And I meant (x-4)^4 * (ln|sqrt(x-3)|)/(x^2-x+76)

As in (x-4)^4 times (ln|sqrt(x-3)|) all divided by (x^2-x+76)
modu-what?

Just wondering how observant and maths-savvy you lot are; only three questions at the moment but I'll post more later.
Apologies for the content; I'm tired and can't think of anything better.

1. If person A earns £1.00 and person B earns £0.75, how much more (as a percentage) does person A earn?

2. How much less does person B earn as a percentage?

3. 6 x 7 x 378 x 2 x 97.5 x 1973 x 56 x 72.835 x 819 x 58 x 2 x 19 x 56821 x 956 x (4-2^2) x 19.627 x 57 + (15) x (82-3^4) - (16) + 1 = ?


Put your answers in white text or something, please, so that other people can answer as well.

The answers are in white text below.

1. 33.3...%
100 - 75 = 25
75 / 25 = 3
100 / 3 = 33.3...

2. 25%
100 - 75 = 25
100 / 25 = 4
100 / 4 = 25

3. 0
6 x 7 x ... x (4-2^2) [This equals 0; when we multiply a number by 0, we get 0. Therefore the answer is 0 at this point.] ... + (15) x (82-3^4) [We've been multiplying 0 up until this point, yielding 0 each time; however, here, we're adding 15 and multiplying by 1, yielding 15.] ... -(16) [15 - 16 = -1] + 1 = 0
Voila!

Why did you have to be observant?
To spot the key words in questions 1 and 2 and the key numbers and operations in question 3.

I actually got them right. I've had a lot of similiar questions like the third one here in school were they try to make it look hard but actually it's easy.

The square root of a number is both positive and negative. 3*3 = 9 and -3*-3 = 9. You have to include both as they both satisfy the condition.

And I meant (x-4)^4 * (ln|sqrt(x-3)|)/(x^2-x+76)

As in (x-4)^4 times (ln|sqrt(x-3)|) all divided by (x^2-x+76)
modu-what?Doh! It's been nearly 4 years since I last studied maths. It really is beginning to show. >.<

The modulus of a number is its magnitude. ie |-4|=4 I'm sure you new that already. Just not the name of the operation.
http://en.wikipedia.org/wiki/Absolute_value
Apparently 'modulus' is British English.

Doh! It's been nearly 4 years since I last studied maths. It really is beginning to show. >.<

The modulus of a number is its magnitude. ie |-4|=4 I'm sure you new that already. Just not the name of the operation.
http://en.wikipedia.org/wiki/Absolute_value
Apparently 'modulus' is British English.
We call it absolute value (in math) or magnitude (in physics).