Math Is Fun Forum

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Jane’s puzzles

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Why did the vector cross the road?
It wanted to be normal.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

Hmm … very interesting. That may work – but the man will have to determine the areas very precisely. He may not be clever enough to do that though – assuming he’s only your average Wild West man about town, who doesn’t know anything about trigonometry or Pythagoras’ theorem.

Nevertheless it is a logical possibility. I have another solution in mind, though.

Kurre

Member

Registered: 2006-07-18

Posts: 280

Re: Jane’s puzzles

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

TheDude

Member

Registered: 2007-10-23

Posts: 361

Re: Jane’s puzzles

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Wrap it in bacon

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Jane’s puzzles

I've improved my answer, if anyone's interested. Now it requires no movement between cuts and only simple measurements.

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Why did the vector cross the road?
It wanted to be normal.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

Nice job, Mathsy.

Kurre

Member

Registered: 2006-07-18

Posts: 280

Re: Jane’s puzzles

Still dont get it, doesnt the puzzle clearly state that the bar must be cut into 11 pieces??
Or is it my english that is failing?

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Jane’s puzzles

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Why did the vector cross the road?
It wanted to be normal.

Ironvein

Member

Registered: 2008-06-17

Posts: 1

Re: Jane’s puzzles

In the 'dropping balls' puzzle, it is said that if the ball breaks on the 14th floor then you only have to test 13 more times to find the limit. I'm not sure how this test solves the problem. If you break both balls you are fired. Now you know the ball breaks on the 14th floor so you test up to the known limit (14), the only flaw in this problem is that the person dropping the ball may have overshot the balls maximum stress right on the first toss. That is to say, the ball might actually break at the 10th floor, not the 14th. It is going to be a rude shock to the dropper when he shatters his second snooker ball on the 10th floor and gets fired.
   So in the question the number of times needed to drop and test the ball may not be 14 times. It could be less depending on the toughness of the balls or lack thereof.
  The only sure way to test would be to drop one ball one floor at a time, when it finally shatters you've found your limit and you still have on ball left and your job is intact.
  Unless I'm missing something here. Which is entirely possible. The main item that I was pointing out was the danger in overestimating the toughness of the snooker ball when you go to do your first toss.
Roy

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

#15

What is special about the numbers 9–18 in Roman numerals?

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Jane’s puzzles

Ironvein, I think the problem is just to find the lowest level at which they break. He gets fired if he breaks both the balls before he finds this out, because if that happens then he can't ever answer the question. If a second ball breaking gives enough information to get the answer then it's alright.

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Why did the vector cross the road?
It wanted to be normal.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Jane’s puzzles

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Why did the vector cross the road?
It wanted to be normal.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

That is also true, but I wouldn’t call that special either.

Okay, I think I have to change the question a bit.

#15′

What is special about the two groups of numbers 1–8 and 9–18 in Roman numerals?

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,267

Re: Jane’s puzzles

I am not too sure, but I guess.....

Last edited by Jai Ganesh (2009-03-01 01:26:52)

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

Nope, not the answer I have in mind.

Last edited by JaneFairfax (2009-03-01 02:16:35)

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,267

Re: Jane’s puzzles

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

That’s true, but it’s still not what I have in mind.

Looks like I need to give some help.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

Quite clearly none of you are going to get it. Oh well.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,267

Re: Jane’s puzzles

Thats a very good answer! If it is your own question, well done!!!

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

Of course it’s my own question. Did you think I would stoop so low as to steal an idea that is not mine?

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 46,267

Re: Jane’s puzzles

JaneFairfax,
That is not what I meant. Look, members post questions, jokes, and many other interesting information in the forum. Not all ideas are our own. I admit I post questions, some of which come to my mind at that instant, and many of them are taken from other sources. That does not make me a plagiarist, nor does that mean I am stooping. The intention is to share our knowledge, wisdom, experience, and humor. If you think every post, every puzzle, every joke is the work of the member posting it, you are wrong. 
I only hope you'd be a bit more polite and understanding when you post.
You are a very very wise member.  I am sure you'd understand.

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Jane’s puzzles

Of course it’s my own question. Did you think I would stoop so low as to steal an idea that is not mine?