Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#76 2014-09-21 23:48:11

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Permutation Problems

It works!


'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'
I'm not crazy, my mother had me tested.

Offline

#77 2014-09-21 23:49:22

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Permutation Problems

And the answer for 5 would be?


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#78 2014-09-22 00:14:14

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Permutation Problems

231


'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'
I'm not crazy, my mother had me tested.

Offline

#79 2014-09-22 00:18:38

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Permutation Problems

That is correct. Very good!


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#80 2014-09-22 00:27:44

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Permutation Problems

Thanks!


'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'
I'm not crazy, my mother had me tested.

Offline

#81 2014-10-04 14:24:15

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Permutation Problems

In a remedial math class, the teacher decides to seat the students in an IQ order. The seats are setup in a way that they appear in a horizontal line. The order is such that when a hypothetical person x is to the left of a hypothetical person y, and x is not more than 8 IQ points higher than y.

For Example, Say that in the math class, there are five students that have IQs of 60, 65, 70, 75, and 80. The students would be put in an order of 60, 70, 65, 80, 75.

So, if the class had 20 students with IQ scores: 20, 25, 30, 35, 40, 45, 50, 55, 60, 64, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110. How many different ways are possible to place these students in an order defined above.

#Combinatorics #IQ


'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'
I'm not crazy, my mother had me tested.

Offline

#82 2014-10-04 18:29:04

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,049

Re: Permutation Problems

Hi Agnishom

In the example, isn't 70-60>8?

Last edited by anonimnystefy (2014-10-04 18:29:25)


“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
The knowledge of some things as a function of age is a delta function.

Offline

#83 2014-10-04 19:08:21

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Permutation Problems

Yes, but 70 is to the right of 60


'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'
I'm not crazy, my mother had me tested.

Offline

#84 2014-10-04 19:26:52

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,049

Re: Permutation Problems

Ah, okay, I get it.


“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
The knowledge of some things as a function of age is a delta function.

Offline

#85 2014-11-04 03:48:50

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Permutation Problems

Problem fell victim to dynamic programming


'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'
I'm not crazy, my mother had me tested.

Offline

#86 2014-11-04 07:40:07

ShivamS
Member
Registered: 2011-02-07
Posts: 3,648

Re: Permutation Problems

Agnishom wrote:

In a remedial math class, the teacher decides to seat the students in an IQ order. The seats are setup in a way that they appear in a horizontal line. The order is such that when a hypothetical person x is to the left of a hypothetical person y, and x is not more than 8 IQ points higher than y.

For Example, Say that in the math class, there are five students that have IQs of 60, 65, 70, 75, and 80. The students would be put in an order of 60, 70, 65, 80, 75.

So, if the class had 20 students with IQ scores: 20, 25, 30, 35, 40, 45, 50, 55, 60, 64, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110. How many different ways are possible to place these students in an order defined above.

#Combinatorics #IQ

It might be best to halt discussions on the solution to this problem on here and on Brilliant as this is a question that is a part of a mathematics competition that will accept submissions until November 5, 2014.

Offline

#87 2014-11-05 02:03:08

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Permutation Problems

I wish I had seen this earlier, I just mailed my solution to Axas.

What competition is that?


'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'
I'm not crazy, my mother had me tested.

Offline

#88 2014-11-05 02:09:22

ShivamS
Member
Registered: 2011-02-07
Posts: 3,648

Re: Permutation Problems

Agnishom wrote:

I wish I had seen this earlier, I just mailed my solution to Axas.

What competition is that?

That guy who posted it on Brilliant has asked the problem on SE and PF already (locked on SE and deleted on PF).

The competition is USAMTS.

Offline

#89 2014-11-05 02:10:55

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Permutation Problems

Yes, and he deleted it on Brilliant when I pointed out that he has posted in SE already


'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'
I'm not crazy, my mother had me tested.

Offline

#90 2014-11-05 02:39:23

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Permutation Problems

Got some of that happening in here too.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

#91 2014-11-05 02:43:23

Agnishom
Real Member
From: Riemann Sphere
Registered: 2011-01-29
Posts: 24,974
Website

Re: Permutation Problems

I think it is November 5, already


'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'
I'm not crazy, my mother had me tested.

Offline

#92 2014-11-05 07:40:18

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Permutation Problems

Hi;

Did not mean that one there are others coming in with contest problems.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Offline

Board footer

Powered by FluxBB