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#1701 2013-04-13 13:59:10

Agnishom
Real Member
From: The Complex Plane
Registered: 2011-01-29
Posts: 14,390
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Re: Is this cool with you?

That is where I am getting those problems from


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'Humanity is still kept intact. It remains within.' -Alokananda

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#1702 2013-04-13 15:47:27

anonimnystefy
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From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

I wonder if bobbym has a devious variation of the last problem he will be posting soon.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1703 2013-04-13 16:58:49

bobbym
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From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

Nothing devious ever entered my mind.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1704 2013-04-13 17:01:58

anonimnystefy
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From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

I would call many of the problems you pose devious. The 9's problem is pretty devious if you ask me...


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1705 2013-04-13 17:06:11

bobbym
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From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

It is not devious, just impossible,


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1706 2013-04-13 17:08:42

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

Impossible => devious.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1707 2013-04-13 17:10:39

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

It is computationally pretty simple if I just had someplace to put the numbers...


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1708 2013-04-13 17:14:53

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

Why not buy a supercomputer? smile

Anyway, can we expect a new problem here soon?

Oh, and, speaking of problems, how's your back doing?


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1709 2013-04-13 17:16:16

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

Worse than ever.

A supercomputer? No one in their right mind would let me near one.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1710 2013-04-13 17:19:14

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

I am sorry to hear that. Have you been to a doctor?

Well, I'm guessing you would either rule the world or break the supercomputer.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1711 2013-04-13 17:23:39

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

Doctors? Thanks to them I have extra problems.

I would try to take it apart and break it.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1712 2013-04-13 17:27:05

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

The only problems doctors can cause you are money problems. I suggest you visit him. Or at least go and get a massage.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1713 2013-04-13 19:34:30

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

I wish that were true. I prefer the pain rather than the lizard.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1714 2013-04-13 23:05:05

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

They've always helped me so far.

When can we expect a new problem in here?


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1715 2013-04-13 23:19:03

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

I am being kept busy fighting spammers, monitoring arguments and answering homework questions.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1716 2013-04-13 23:24:37

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

Which homework questions?


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1717 2013-04-13 23:35:24

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

http://www.mathisfunforum.com/viewtopic.php?id=19217

I still do not have any idea what he even wants. I ask a question he avoids it and goes on explaining something else. This is very non productive.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1718 2013-04-13 23:38:48

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

Oh, that. It does seem pretty unclear what he wants.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1719 2013-04-13 23:45:30

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

He will not explain or point me to the book, title and author. I am sure it is stated better there.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1720 2013-04-16 14:16:50

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

bobbym wrote:

New Problem:

A used car salesman has 8 lots with 100 cars each. He wants to repaint all his cars. Each day one of his employees picks 35 cars at random from all his cars and paints them. Then he returns them to the lots. Since they do not keep records some cars get painted more than once. After 23 days the manager would like to know how many cars have been painted. he wants to do this without going down to the lots. Can you figure it for him?

A says) 522.
B says) I do not have an answer but I know that A's answer is wrong.
C says) I got that, and it is definitely wrong.
D says) No answer yet.
E says) I got it!

This can also be done using linearity of expectation.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1721 2013-04-16 16:31:45

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

Well, let me see please.


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1722 2013-04-16 20:33:32

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

Well, I just give each car a random variable which is 1 if the car is painted and 0 if not. Its expected value is E[Xi]=1-(1-35/800)^23. The expected number of painted cars is E[X1+X2+...+X800], which, based od linearity of expected value, equals E[X1]+E[X2]+...+E[X800]=800*(1-(1-35/800)^23), which gives the correct answer.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1723 2013-04-16 21:36:37

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

Hi;


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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#1724 2013-04-17 02:29:06

anonimnystefy
Real Member
From: The Foundation
Registered: 2011-05-23
Posts: 14,847

Re: Is this cool with you?

I like that it can be easily generalized.


“Here lies the reader who will never open this book. He is forever dead.

“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment

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#1725 2013-04-17 02:34:58

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 81,748

Re: Is this cool with you?

Did you see my solution?


In mathematics, you don't understand things. You just get used to them.
I have the result, but I do not yet know how to get it.
All physicists, and a good many quite respectable mathematicians are contemptuous about proof.

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