/sci/ - Science & Math

>>7565916
Yeah but the question is poorly asked

>>7565916
One cut throuh takes 10 minutes. You need to saw through the other board 2 times to get 3 pieces. Assuming you don't count the first example board this should take 20 minutes since 10+10=20 or am I missing something here?

I mean...
If it takes someone 10 min to saw a board, it doesn't matter how many pieces. Every piece would take 10 min to saw.

The second cut doesn't have to go through the whole board.

15 minutes is correct.

>>7565923
>>7565924
>>7565925
Fucking retards

>>7565916
Theres one thread to ask for solve questions?

>>7565926
>>7565932
The image clearly shows that the board isn't a square though.

>>7565932
>Fucking retards
Really?
Here's my 12 minute solution.

>>7565932
Hope youre kidding....

>>7565936
So why not just cut 2 corners instead of halfway through? Should take 4 minutes if you think yours takes 12.

>>7565936
here's my arbritrary short time solution.

You're all wrong. The amount of time it takes to cut the board depends on the thickness. Not the length.

7^x-y=1/7

log3 √ x+y - log3 √ x-3=1

The base is 3.

Please i do not know what to do with this √.

It's a very poorly worded question.

>>7565953
It would be a very nice Layton puzzle though.

>if she works just as fast
>fast
>10 min for what is pictured as 1x1" board

Lol

Also, the image off to the side is confusing. appears to be a 2x2 and not a flat sheet.

>>7565923
>>7565953

how else could it be asked? i cant see how it could be 15

>>7565953
im not familiar with /sci/ memes are you making joke? I worry because you kids these days with your common cores may actually be this retarded and it concerns me.

>>7565953
>>7565923
Is this a new meme? That every time there's an obvious question that someone gets wrong you say that the question is poorly worded?

>>7565934
>implying images are to scale

>>7565951
Length is thickness if you are cutting orthogonal to the length.

It's a proportion question

so you would do:

(10/2)=(x/3)

cross multiply

10*3=2*x

simplify

30=2x

divide

x = 15 (minutes)

SAGE HIDE REPORT

>>7566013
Are you dumb as fuck bro?

>It took Marie 10 minutes to saw a board into 2 pieces.

Which means that she sawed the board ONCE.
You only saw a fucking board once if you want to make 2 pieces out of it you stupid idiot.
1 cut = 10 minutes
2 cuts = 20 minutes.

Come the fuck on /sci/ this shit isn't even hard.

>>7566031
A paint drawing for those too fucking dumb to get it.

>>7566031
>>7566039
>tripfag
opinion trashed

>>7566046
>no idea about tripfags in /sci/

gtfo you newfag

>>7566031
>been here long enough to tripfag
>still cant recognize an obvious troll

lurk moar you dumb fuck

>>7566031
Are you autistic? The 2 the on the denominator represents pieces, not cuts.

>>7566039
The problem say ANOTHER BOARD.

A N O T H E R B O A R D

not the same board retarded trip fag

>>7566052
Hi there!
You seem to have made a bit of a mistake in your post. Luckily, the users of 4chan are always willing to help you clear this problem right up! You appear to have used a tripcode when posting, but your identity has nothing at all to do with the conversation! Whoops! You should always remember to stop using your tripcode when the thread it was used for is gone, unless another one is started! Posting with a tripcode when it isn't necessary is poor form. You should always try to post anonymously, unless your identity is absolutely vital to the post that you're making! Now, there's no need to thank me - I'm just doing my bit to help you get used to the anonymous image-board culture!

>>7566071
Hi there friendly anon!
If i stop using my trip all my fans will think i'm dead! Sadly there are not many of them left BUT i have to remind some that i'm still alive!
Thank you for your kind words Mr.Anon and have a wonderful day!

>>7566070
>>7566067
>thecringe.jpg

>>7566084
>fans

Kill yourself my man

>>7566039
its says how long does it take to cut another board into 3 pieces but it still would take 20 minutes

ITT autists that never cut a board

it takes the same fucking amount of time no matter what

saging this fucking trash bait

If it takes you 10 minutes to saw a board into 2 pieces, it means that it takes you 10 minutes to make a "cut".
If you want to saw a board (a different board, not the same one that is already cut) into 3 pieces, you would need two "cuts" so the single board could be divided in 3. So for each "cut" the time taken is 10 minutes.
Now, the answer would be 20 minutes if the problem was only "slice into 3 pieces".
However, since it indicates that you will also cut the board twice as fast, it means that each cut will now only take 5 minutes instead of 10.
Since you have to do 2 cuts, it would be 5 * 2 which is 10. In other words, you cut twice as much with twice the speed, which ends up taking the same amount of time. Also when it says you "cut" the board in 3 parts, it is very obvious that you are supposed to saw it in 3 equal parts, not a half and then half of one half you cut, so you end up with 1/3 1/3 and 1/3, instead of 1/2 and 1/4 1/4 like many have suggested.

The final answer is therefor 10 minutes.

>>7566110

OH WAIT WAIT WAIT.
I just realised that I didn't read the problem correctly. I read that you would cut it twice as fast but it says JUST AS FAST.
Then the answer would be 20 minutes

>>7566110
>it indicates that you will also cut the board twice as fast
What the fuck, it literally says that she cut the board just as fast

>>7566113
I just said that in my second answer.. I corrected myself since I read the problem wrong at the first time. I corrected myself if you see my answer to myself. My final answer was 20.

>>7566117
Cuck detected

>>7566112
fucking finally someone gets this shit.

>>7566120
Sorry? I don't understand what you're trying to imply, I only said that the answer was 10 minutes..

>>7566117
>3,14
>,
>comma and not period
>name fag
Didn't even begin to read your post fam

>>7566125
I MEAN 20 (fak I miswrote it again) -.-

>>7566129
>-.-
>fak
>,
end yourself my man

>>7566127
Are you serious? It's a period (dot) if you live in america..
Not every country uses a period -.-
I'm from Europe and we use comma for 3,14 instead of 3.14
The correct way depends on where you live, there is no definition.
What are you even doing here if you don't know that..?

>>7566134
see
>>7566132

My man sudoku yourself tbh my man

>>7566132
Are you trying to make me mad? kek
If you think I would care about someone who writes something to me on 4chan you would be very wrong. You're just trying to troll me but it's not like I really care. I just wanted to answer this problem. And I gave my answer (20) to the problem. I'm not here to discuss with kids with no life.. :l

>>7565961
lol, I was wandering the same thing

>>7566134
>The correct way depends on where you live, there is no definition.
>What are you even doing here if you don't know that..?
Here on /sci/ almost everyone (including Euros) uses the "." for a decimal point.

>>7566137
not even the same guy but
>,
>kek
>20
>:|
>-.-
>namefag
smfh tbh kia yourself imo my fam

>>7566140
So you're implying I should adopt the american way and use dot when posting here? I mean, I don't mind changing it if it bothers you too much but I honestly don't see the big deal. Most countries use comma, so maybe the few ones that use dot (UK, USA, Australia, etc..) should change. Or maybe no one should change at all..
But if you insist, tell me and I shall change my name to a 3.14

>>7565932
>>7565936
>>7565943
/sci/ never disappoints

>>7566142
I don't see where the problem is, sorry.

f(1) = 5
f(2) = 10
f(3) = 15
f(4) = 20

>>7566159
I believe that would be incorrect.
It takes 10 minutes to saw a board in 2 pieces, but it doesn't take 5 minutes to "saw a board into 1 piece" since that does not exist, you would not be sawing anything, and it would take you 0 minutes. Also when you saw a board into 3 pieces, it is obviously assumed that you will have 1 board divided by 3, which would divide the board in 3 EQUAL pieces, so 1/3 + 1/3 + 1/3.
Same applies to 4 pieces, 1 = 1/4 + 1/4 + 1/4 + 1/4
(since it would be obviously a new board, not cutting the same one into 2 pieces, and then 3 and then 4. each time you cut it into different pieces, it's assumed that you have a new board)

>>7566137
refer to
>>7566142
>>7566136
>>7566132
>>7566127

>>7566110
>>7566112
>>7566134
>>7566137
>>7566145
>>7566168

fucking cancerous, refer to >>7566256

>>7566260
:/ why you being so mean lol xD

its very simple. if one cut through a thickness of wood takes 10 minutes, then two cuts will take 20. period. end of story.

source: i've sawed lots of wood.

>>7566264
I've got some wood here you can saw through if you catch my meaning ;)

>>7566260
stfu fag ur autism lvl is over 9000

>>7566256
lel pleb kill urself

>>7566278
If I actually did you would be held accountable and tried for man slaughter. Not so tough now eh?

sure is right. majors subject likely

>>7566281
actually no one would care cuz i'd be doing a favour to the world

>>7566289
I have a lot of potential to contribute to society so nah

>>7566290
rlly? weren't you dat dude who was saying shit about the dots and commas? u really have lots to contribute sure pleb

>>7566293
My first order of business is convincing the world to adopt the superior period instead of the comma for numbers.

>>7566297
Dude, actually the comma is way more used than the dot.
Check it urself http://www.statisticalconsultants.co.nz/blog/how-the-world-separates-its-decimals.html

Anything else?

>>7566301
>>Anything else?
What do you mean?

>>7566302
u sure you still want to "convince" the world to adopt "superior" period?
i mean, it's way more obvious that it should be the other way around.
ur probably american i guess, so ur defending your own country's syst. and make evreyone else change for u like if you were superior

should 100 change for 1 or 1 change for 100?
just sayin

>>7566306
The period "." uses less space than a comma ",".

Why shouldn't the period be used?

Yes, It's elementary school for fuck's sake.

>>7566310
so ur only motive for why the period should be adopted everywhere is cuz it uses less space?
so let's change about every other country just because a "." and a "," are very different, and changing the , to an . will change everything in math and in life. it will have HUGE impacts on the world as we know it.

i don't see why we should use period, but i see why we should comma:
more countries use it. (seems good enough)

seriously, between . and , you can probably save up 1 nanometer

"lots of potential to contribute to society" (1 nanometer)

>>7566039
>>7566031
>Tripfags are always retarded

It clearly states that it takes 10 mins to cut a board into 2 pieces, so <div class="math"> 10~mins = 2~ pieces \Rightarrow 5~mins = 1 piece </div> So we want to cut the board into 3 pieces which gives 15 mins.

This isn't a hard problem, I bet you're one of those sub-70 IQ physicists.

>>7565959
It could be asked in the form "it takes X minutes to do two tasks, how long does it take to do three tasks?"

f(0) = 0
f(1) = 0
f(2) = 10
f(3) = 20
f(4) = 30
f(5) = 40

f(x) = 10(x-1)
f(x) = 10x - 10

I love you /sci/

>>7566145
Using the comma instead of a dot is just retarded. Point is easier to say than comma, you don't get mixed up when writing big lists of numbers in a sentence, and you can use commas to separate place value to make monetary expressions easier to read.

>>7566313
>changing it will have HUGE impacts on math and science as we know it!

Considering the US, UK, China, and India all use the decimal point, the world of math and science would see barely any impact.

>>7566313
>more countries use it
>countries with more people in them don't use it

Which one of these doesn't matter? Hint: the first one.

>>7566334
>f(x) = 10x - 10

f(0) = 10(0) - 10
f(0) = -10

kek

>>7566347
>implying US, UK, China and India have bigger impact on math than all Europe combined.
Also "point" isn't easier to say in all languages.
Not everyone uses english as their main language.
While you can write a dot and many may not see it, a comma will always be seen.
It makes way more sense to write comma than dot in so many ways, but I don't see why we should argue so much about it. Really not worth discussing. It's like discussing if the word should be "aluminum" or "aluminium" and that one should change to the other because it's easier/any other reason.

>>7566354
fuck u m8, it was implied to be piecewise

f(x) = 10x - 10 if x > 0
f(x) = 0 if x = 0
x is only defined for naturals

>>7566147
toppest kek

>>7566328
you can't saw a board in "1 piece". That's not a division..
That would take 0 minutes

>>7566347
That could be a good point, but I'm pretty sure that if you sum all the other countries, their combined population would still be greater than these few like China, USA and others.

>>7566347
Well I still think it doesn't really matter but I prefer to use comma.
You may reply but I wont answer again since I'll be leaving now, so I can't.

>>7565932
>mfw that way it will take someone 20 minutes to cut a board into infinitely thin pieces

Anyone here have good resources to learn propositional and predicate logic?

>>7566378
>implying blah blah blah

That's exactly what's being implied. Also, name one language where the word for point is longer or takes longer to say than the word for comma. Protip: if you can, it's a rare exception. The opposite is the case in literally every romantic language, except maybe Greek, which is ironically where the word "comma" comes from. Also, this is much more important than spelling differences or even language differences. The vast majority of programming languages use the decimal point, even when they are used in countries that don't. Incorrect syntax won't run, plain and simple. Why do you insist on living in the past?

>>7566354
Yes, you can go backwards in time by dividing a board into 0 pieces.

Never divide by zero.

I will explain why the answer is 15. And those that argue it is 20 are mistaken, but the question IS indeed poorly-worded.

The question is equivalent to:

It took a hose 10 minutes to pour water into 2 pools. If it works just as fast, how long will it take the hose to fill 3 pools?

The two questions are the same, the only difference is the practical circumstance.

Notice how, while a board can be cut into 3 pieces in two cuts, each of which takes an equal amount of time, the same does NOT apply to the pools: where filling a pool is an act that can't yield the exceptional case of producing another filled pool - as can cutting a board in two.

Because of this, the answer IS a proportion question. It only seems deceptive because our understanding of how to cut boards got in the way. Those that were mistaken treated the question as a puzzle rather than a test of one's understanding of proportions.

>>7566532
It takes 7 minutes to hard boil one egg.
How long does it take to boil three eggs?

>>7566532

>>7566328
you're retarded. 2 pieces is ONE CUT. 3 pieces is TWO CUTS. 1=10. 2=20.

>>7566542

This is very clever, but it is not the same question.

Notice that your question is not the same as:

"It took a hose 10 minutes to pour water into 2 pools..."

it would be the same as:

It takes 10 minutes to pour water into a pool. How many minutes would it take to pour water into 8 pools?

This is not a rate of change question. We are not provided with a limitation on the rate of a given object. It is just a statement of fact with no bounds.

>>7566532
retarded. you don't cut a board for 10 minutes, halfway through get one piece, and then by the 10 minute mark have 2. no. its one piece for 9 minutes and 59 seconds, and then it becomes 2 pieces.

another equal cut will take just as long.

>> It only seems deceptive because our understanding of how to cut boards got in the way.

>>you got it wrong by being objectively correct

you're what is wrong with the world.

>>7566542
>How long does it take to boil three eggs?
If it takes one man an hour to dig one hole, how long does it take two men to dig half a hole?

>>7566583
15 minutes

>>7566586
>15 minutes
There's no such thing as "half a hole".

>>7566587
yes there is. it'd be 3 feet deep, 2 feet wide, and 4 feet long.

>>7566587
It obviously means a hole half wide than the first hole.

2 cuts = 2 pieces + 1 board (10 minutes = 2 cuts)
3 cuts = 3 pieces + 1 board (15 minutes = 3 cuts)

>>7566632
Here is a pic.

>>7566632
NO. NO. NO.

>>7566643
Obviously the board she is cutting is much too large for her purpose, so she saws off 3 pieces, instead of sawing the board in half two times. Have you ever worked with wood constructions?

What if the board is circular?

>>7566656
>>7566656
there is no such fucking assumption. i'm a skilled woodworker. it wouldn't even matter. a cut is a cut. if the first takes 10 the second takes ten.

it says, she saws a board into two pieces. there is no implied woodworking and design elements. if we had to assume anything, we'd assume she wasn't an idiot and designed around the available materials and would be evenly dividing one board and then triple dividing another.

>>7566329
not the same question

Infinite amount of time. Because after the first saw, she said fuck it and stopped bothering.

>>7566713
Can I screencap this epic post and upload it on reddit?

>>7566501
Wrong. Just cutting the left half into two pieces would be another five minute cut. Kill yourself.

>>7566725
Sure my reddit friend.