interested in mathematics ?

[Geronimo]

here's the problem:

you've 39 glyphs for 7 fields ..

a) how many possible combinations are there ?

b) what's the mathematical probability to get 1 definite combination ?


my guess:

a) 137231006679 possible combinations ..

b) 0,000000000729 %

what would u think ??

 

[padders]

uh oh... we had a very long discussion on the number of permutations and problems with it. Have a look at the thread Chevron7 (i think that is what i named it) under technical section.

 

[MythingLink]

Yeah, it was Chevron 7 ... LOL!

Cheers,

 

[jsc]

I'm boggled too many permutations. And that is just for the planets that at the time the gates were made supported life. Will keep the writers busy with places to go for a while!

 

[Geronimo]

oops ...

think my calculation is wrong ....

forgot that you can't use 1 glyph more than once ..

think i must begin new calcuation )

 

[padders]

hehe.. look in the chevron 7 post we go round and round and round in circles (no pun intended).

Before giving a number quote your assumptions:

From my maths i thought it was:

39C7 which is oh i cant remember someting like

15380937

if you could use the same chevron lots of times it would be

39P7

7.75 x10^10

you got your number from 39!

this is not correct. That is the number of ways of arranging all 39 chevrons.

so say you had only 5 chevrons:

A B C D E

and you had to pick 3.

your way is to go 5! which is 5x4x3x2x1

but it is not that as we need them in group of 3.

so it is 5P3

which is the same as saying

5! - 3!
-------
2!

(and that calculation, is for permutations ie AAB and ABA are allowed.

 

[padders]

Originally posted by jsc
I'm boggled too many permutations. And that is just for the planets that at the time the gates were made supported life. Will keep the writers busy with places to go for a while!

Nah, we are trying to find "possible addresses" they will not all have worlds to actually gate to (or stargates for that matter)

 

[Martouf]

Hehe, padders is good at maths
Well i don't mean to brag fellaz but i am in the Top maths class for my grade ...... but do not get any of this

I don't get why it is so hard to not guess an address?

 

[bel]

OK the maths teacher in me can't take any more!!

The method of calculating the number of permutations when order matters and no choice can be used more than once is fairly easy.

For 5 symbols and addresses of three symbols there are 5 choices for the first symbol, 4 for the second (not using the one already chosen) and 3 choices for the third.

Number of combinations is 5x4x3 = 60

So for a Stargate of 39 symbols - one is always the seventh symbol - you have a choice of 38 for your first symbol, 37 for the second and so on to six symbols.

Combinations = 38x37x36x35x34x33 = 1987690320

If order did not matter you divide this number by the number of combinations for the six symbols ie 6x5x4x3x2x1 = 720. This is what happens when you calculate the odds on the UKs National lottery because order doesn't matter then just the numbers so the number of combinations is
49x 48x47x46x45x44/720 = 13983816.

In factorial notation its

38!/34! or 38!/34!x6! if order doesn't matter

Hope this helps

 

[padders]

Wehay.. that was it.

I needed to go back to my Stats 1 book, my teacher i don't think would have been proud

 

[jsc]

Bel,
Welcome to the Talkstargate Forum! Thank you for posting. I think you have cleared up a problem we have been having in the thread! You are a Math teacher? Cool. We have all types of people here doing all sorts of interesting things.
You are a nice addition!

 

[Martouf]

Welcome bel.

 

[padders]

bel, did you de-lurk to post that both funny and kind.

I either loved or hated my maths teachers. We had some of the "coolest" teachers, most friendly and good fun ones and then some of the most boring, annoying and awkward ones. I am sure you are the former !

 

[Geronimo]

hi'ya bel !

thx for this explaination but i have a question:

at 1st try u have 39 symbols avaiable so why do you start with 38x37x36x..... ??

thx

 

[padders]

think of it like this:

The number of choices you have for the first symbol. There are 39 choice so 39. x by the number of choices you have for the second symbol. As you can't use the one you already have used there are only 38 left thus it is 39x38..... etc

 

[padders]

arr i am a twit. If there are 39 symbols then it is 39 but i think it was to do with the symbol of origin being the same or something? Ignore my previous post!

 

[bel]

Geronimo

I started with 38 because I am assuming that one of the 39 symbols is the point of origin and cannot be used so you only have 38 symbols to choose from so the sum starts with 38 and only multiplies six numbers as the seventh is always the same - the point of origin.

Always a bit of a risk admiting to be a maths teacher - the subject is often not a popular one! There are however lots of maths teachers who are Stargate and other sci fi fans, at least three in my school alone. The other subject whose teachers are big into sci fi at my place is English, something I always find surprising. I know it's hard to believe but teachers can be human too - my students find it hard to believe I even watch TV never mind drool over Jack O'Neill.

Nice to meet you all - help with maths always available!!

 

[jsc]

Bel,

Welcome back to the forum. Glad you hae been so helpful and are offering help for the future. No, it isn't risky here (yet) to admit you are a math teacher! Glad you feel like posting. If something interests you POST. If you want answers or want to make comments feel free, if you don't find what you want open a thread in the appropriate area!

Mostly just kick back and enjoy!

 

[Geronimo]

thx ...

that was my thought why u begin at 38 ..