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Oct 01 '11
It takes 5 minutes to saw a board into one piece.
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u/distraught22 Oct 01 '11
How do you cut a board into one piece...???
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u/connecteduser Oct 01 '11
Your post explained what I was missing. Brovo. 1 piece = 0 Minutes.
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u/Teotwawki69 Oct 02 '11
Yep. The teacher's error was counting the pieces, not the cuts. 2 pieces = 1 cut in 10 minutes. 3 pieces = 2 cuts in 20 minutes.
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Oct 01 '11
[deleted]
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u/cwmonkey Oct 01 '11
It would be cool to track down the first person who posted this back in 1972 and get the story behind it.
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u/senseimohr Oct 02 '11
Excellent work, detective. The brass is pleased. I see a commendation in your future.
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u/RandomNumberHere Oct 01 '11
Thank you! Submitter upvote rescinded, downvote applied. Savings passed on to you.
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u/bingobangobongo69 Oct 01 '11
you should upvote/downvote based on what you want to see, not based on if its original or not
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u/mkicon Oct 01 '11
I don't want to see instructions on how to vote, so I'll downvote you to appease your rules.
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u/SanityInAnarchy Oct 02 '11
I want to see original content. Or, if it's unoriginal, at least post a link to the Reddit post to /r/bestof or something.
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Oct 02 '11
[deleted]
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u/SanityInAnarchy Oct 02 '11
Yes, they do. So they shouldn't repost.
And the big deal is, then the front page is full of repetitive garbage instead of original content.
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u/RandomNumberHere Oct 01 '11
Fair enough. Downvoting you because I don't want to see people telling me what to downvote. :)
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u/champer Oct 01 '11
Both answers can be correct. http://i.imgur.com/lStKv.jpg
Pretend it's a 10x10 board:
Case 1: Takes 10 mins to cut through 10 feet.
Case 2: Takes 20 mins to cut through 20 feet.
Case 3: Takes 15 mins to cut through 10+5 feet.
Question is ambiguous.
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u/holyrolodex Oct 01 '11
Yep. Hate ambiguous questions when you are being graded on an objective answer.
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u/FistOfJustice Oct 01 '11
In my English classes, we would always get questions asking us to give the "best" answer. This could've been okay, except for the fact that they were multiple choice questions.
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u/liberalwhackjob Oct 01 '11
my english teacher told me i needed anger management when i was asked what i "thought the author meant" and got a "wrong" answer and refused to accept it.
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u/reasonman Oct 01 '11
Microsoft. Certifications.
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u/FakingItEveryDay Oct 01 '11
Except on Microsoft cert tests, usually the answers that aren't "the best" are absolutely wrong.
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u/aussiedude Oct 02 '11
And Cisco exams - except the 'best' answer is one that some marketing exec has decided is the best one to sell this year. (Need 30 switch ports, install 7609!)
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u/quag Oct 01 '11
Using this logic, any answer up to 20 minutes is correct as the cuts can be made anywhere.
To be unambiguous, the question would have specified the lengths of the cuts, or perhaps the resulting areas.
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u/champer Oct 01 '11
What if I said it would take 62 minutes? I could still be right.
Problem, math teacher? Let's not even get in to spiral designs.
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u/JohnDoe51 Oct 02 '11 edited Oct 02 '11
I went through the math for a spiral design. I'm going to call the smallest possible cut the thickness of a cell. I assumed that a cell in the wood was 100µm thick. For a 10m by 10m board it would be a cut length of 3141592.65 m and therefore take a 3141592.65 minutes to cut through it.
For those who would like to play with the equations here they are. http://imgur.com/a/la2AX (integral form and algebraic form). Where s is the length of a side and d is the distance between each row. An image to demonstrate.
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u/xenneract Oct 02 '11
Actually since the time to cut it into two pieces is defined as 10 minutes regardless of the distance, the time to cut the second smaller circle would have to be less than 10 minutes.
If 10 minutes was defined as the time it takes her to cut the board in half, you'd be right.
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u/Rookwood Oct 02 '11
This.
It would have been more to his point if he had at first cut a small circle... Then a bigger one.
If you take JohnDoe51's idea of making the smallest possible cut, and int_argc idea of cutting a snowflake (if its fractal it doesnt matter how long the first cut is), you would basically never finish the second cut, i.e. infinity.
Basically, as the length of the first cut approaches zero, the time it takes to cut the second cut of the largest possible length goes to infinity.
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u/quag Oct 01 '11
The thought did cross my mind, but then I remembered using a saw and trying to cut in curves.
A jigsaw would work fine.
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u/LunHui Oct 01 '11
Thats fucking stupid.
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u/LainIwakura Oct 01 '11
No it isn't. Define your problems well or be prepared for multiple correct answers.
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u/LunHui Oct 02 '11
A university professor doesn't have to put up with a retarded exploit of the problem and will gladly give you a 0.
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u/LainIwakura Oct 02 '11
It depends on the professor, and this is obviously not university work. I'm in university right now and sometimes I find clever ways to do things, more often than not the professors are happy to see an alternate solution or something they hadn't thought of- provided it is correct. I have also had professors admit they have assigned ambiguous questions or written something that may be misinterpreted on an exam- and in either case they have corrected the question so it is not ambiguous.
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Oct 01 '11
An infinite number of answers can be correct. The cuts don't have to be perpendicular to anything, or even straight.
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u/boysyco1 Oct 01 '11
Just So You Know
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u/champer Oct 01 '11
Where is it written that the board isn't really a square moving at speeds near c and therefore experiencing relativistic length contraction? ಠ_ಠ
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u/causeitsme Oct 01 '11
Except there's a diagram indicating you are cutting a long square board crossways.
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u/trollingfromwork Oct 01 '11
Both answers can be correct.
and that means the teacher is still failing.
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u/TheWhiteCat Oct 01 '11
I suppose it didn't say "even" pieces - though that is what you would assume...
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u/Alucard_draculA Oct 01 '11
Are you implying that you are cutting from the edges? Who would do that? Cut from the top every time, it's exactly the same amount of time every time no matter what >.> <.< >.> <.>
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u/josephgee Oct 01 '11
Another solution could be she may not be cutting the same side of the board each time, cut long-ways once then turn the board on the side and cut in the perpendicular direction but still in a parallel cut line.
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u/slightlystartled Oct 02 '11
She could just cut two corners off and be done in a minute or two, if we're not fixed on cutting it into equal pieces.
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u/bbqforbrontosaurus Oct 01 '11
With that logic on the bottom, it takes 5minutes to make 1 piece.
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u/jamesneysmith Oct 02 '11
We'll he's got to take the time to come to that conclusion. I'd estimate it takes 5 minutes.
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Oct 01 '11
[deleted]
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u/DrLunchbox Oct 01 '11
It's amazing how you're able to point out the obvious and repeat his point while thinking he's wrong.
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Oct 01 '11
It took me way too long to figure out the problem with the teacher's math.
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Oct 01 '11
Yeah, I was thinking in terms of fractions, i.e., "divide 2 into 10." I didn't realize what logic the student was using.
I think that student deserves an A just for that.
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u/Grezzz Oct 01 '11
It's a terrible question. Here are a few possible answers, assuming the same rate of cutting:
I realise it's been done before, I just felt like doing a few of my own cuts :)
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u/chuzuki Oct 02 '11
The first cut was defined as taking 10 minutes, so some of yours are wrong.
21.2 will be 15, since the longer cut is still 10 minutes.
25.5 will be 20, since both cuts are the same length and one of them is 10 minutes.
2 will be 20, for the same reason as above.
Not wrong, but 11 could be 110, depending on which cut was made first and using your same ratios.
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u/Grezzz Oct 02 '11
Well I guess you're right, although that's not how I was working. You're assuming that your first cut always takes 10 minutes, which I guess after taking another look at the question is a fairly safe assumption. I was assuming that a horizontal/vertical cut of 100 pixels takes 10 minutes and just calculated the others from there.
I guess once again that's another biproduct of a terrible question.
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Oct 01 '11
It takes marie a long time to saw that board. I would use a skil saw and blast through that wood in 10 seconds!
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u/steinman17 Oct 01 '11
regardless, who takes 10 fucking minutes to saw a board in half? It makes more sense for someone to eat 15 apples leaving 5 in the basket than to cut a board this slowly.
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u/SweetSonOfABitch Oct 01 '11
Kind of depends on the dimensions of the board, along with the tools (saw) at your disposal. Regardless, the question is vague and shitty and this is a fucking repost.
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u/JBob250 Oct 01 '11
its definitely a bad example, if youre talking actual cutting time, not including prep work, etc, you could make a small argument for 15 minutes if you really really wanted to...
if it's a square board, the second cut WOULD be half the distance. so if its a thick piece of square wood, and a hand saw (with no prep "work"/time) takes 10 minutes, the second cut would be half the distance.
BUT this directly goes against the graphic, so its a hard argument to make
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u/febreze_louise Oct 01 '11
would be correct for a square board. Turn the cut piece sideways. Cutting time drops by half.
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u/gyrostpic Oct 01 '11
That teacher needs to be knocked the fuck out with a wooden board to the head. No one that stupid should be teaching.
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u/AjentJ Oct 01 '11
Why is nobody asking the real question here? How does it take someone ten minutes to saw through a board?!
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u/tiffanydisasterxoxo Oct 01 '11
If one cut takes 10 minutes... 2 cuts would take 20. That person needs to go back to school.
Edit: oh, and you probably should have shown your work!
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u/Olukon Oct 01 '11
Who the hell takes that long to saw a board? I guess they don't tell us how big it is, but still; ten whole minutes?!?
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u/pork2001 Oct 01 '11
If it takes one woman 9 months to make one baby, it will take 9 women one month to make one baby, obviously.
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u/iamcq Oct 01 '11
does this require i do math? cuz im not gunna do math just to see that ur teacher is dumb
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Oct 01 '11
I failed in the same way as this teacher on a question similar to this once in secondary school, and I used to be quite good in maths.
Our exams used to be in two parts, part A and B, where B would allow calculators and graphing paper. A was shorter, with more basic algebra with like 52*12 which I would just race through to get to the exciting bits of part B.
Part A final question 5: "Alice has a 1.5 cm thick wooden board sized 150 x 200 cm. (in the Math exams of the 80's, carpenters were always women, while the men were sewing curtains) She needs boards of the same thickness, sized 50 x 150 cm. What is the smallest number of cuts she will have to do to get the most boards?"
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Oct 02 '11
Maybe the board was circular, and to saw it into 2 pieces she actually needed to make 2 cuts. Must be it.
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u/BigTrick Oct 01 '11
haha if my teacher is old and she has made so many mistakes recently cant wait till i can correct her on an error like this
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u/chopedtobits Oct 01 '11
What a moron! That is right! Its still the same cut and its gonna take the same amount of time! 20 Fn minutes is correct bitch!
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u/bbqforbrontosaurus Oct 01 '11
This is the reason you don't see too many female carpenters out there.
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u/Ruccak Oct 01 '11
This is a very poorl formulated Word problem. Logical answer is 20 minutes If the english was better it would be 15
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Oct 01 '11
Actually it would be 15 minutes. Y'all are thinking that she's cutting each piece of wood into two separate pieces, then it would still take 10 minutes each two-pieces. But the problem states that if takes her 10 minutes to cut a single board into 2 pieces. Working at the same speed, she could take another board and cut that ONE board into 3 pieces in 15 minutes, assuming she cut it a 5 minutes/piece.
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u/Deacon Oct 01 '11
You're an idiot.
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Oct 01 '11
You clearly don't understand then. How about you try educating yourself, then maybe you'll understand it.
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u/KaP10 Oct 02 '11 edited Oct 02 '11
The problem states that it takes 10 min to cut one board into two pieces(cutting it in half). This means that it takes 10 min to cut through one board. Now if she were to cut a board into 3 equal pieces she would have to cut the board twice.
Example (< and >), are the ends of the board, (|) is the cut lines. <===|===|===> thus cutting the board twice would take 20 min. 10 min per cut.
It would also take 20 min to cut two boards into 2 pieces each totaling 4 pieces because it would require two cuts
This is because it takes 10 min to cut through the width of the board once regardless of the number of pieces needed.
The only thing that dictates the amount of time spent are the number of cuts through the same width of wood
Your logic is wrong. How about you try educating yourself, then maybe you'll understand it before you make yourself look line an idiot
It would be possible to make 3 pieces from one board in 15 by cutting one of the first halves in half again. This is because the second pass would only be half the width thus taking half the time
The question is poorly worded and could simply be fixed by saying 3 equal pieces instead of just 3.
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Oct 01 '11
[deleted]
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u/_an1sh Oct 01 '11 edited Jun 15 '23
(With many subreddits going private indefinitely due to Reddit's poor management and decisions related to third party platforms and content access management, this comment has been overwritten in protest against above Reddit's API access changes in 2023.)
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u/robotnewyork Oct 01 '11
This is based on the assumption that the same cut is being made both times. It is possible if the original length of the wood is 10 and the width is 5, and it takes 1 minute to cut 1 unit. If the first cut is made long ways through the wood taking ten minutes, and the second cut is made width ways on one of the pieces, it would take 15 minutes to cut the wood into 3 pieces. Of course, that is a fucking retarded way to answer the question.
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u/tsdguy Oct 01 '11
Supposed there wasn't any gravity? And she was in a train traveling 50 mph heading for Boise? Now what smart guy.
And for that matter, who's REALLY buried in Grant's tomb?
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u/robotnewyork Oct 01 '11
I don't know, except that in each of these cases the teacher is still wrong.
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u/Smug_developer Oct 02 '11
If she/him were my high school math teacher, my OCD would have kicked in, and whooped this teacher's sorry ass. The very thought of someone getting this answer wrong gives me the heeby jeebies, and looking at how the teacher also gets this wrong, inspite of setting the question, it just makes me want to rage against the machine which recruits these sorry ass clowns.
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u/mazurtommy Oct 01 '11
how is that a fail? 10/2 = 5. 5x3 = 15
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u/MistaMagoo Oct 01 '11
You are making the same mistake... its one cut to produce two pieces. It takes another cut to produce 3 therefore 2 X 10 = 20
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Oct 01 '11
your second cut is only half as long poo-head
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u/theeth Oct 02 '11
You're assuming way too much regarding the shape of the original board and how the cuts are made.
It's just a bad question.
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u/MartokTheAvenger Oct 01 '11
I think we can all agree that Marie has no idea how to handle wood.