163!

[Cheung]

Just some sideline trivia:
Correct me on the maths......
There are 163 racquets (or thereabouts on the review list)
If we get a thread asking for a comparison on xx racquet vs zz racquet, there are 163! possible combinations.
Multiply that by four for the replies. What's the answer? Scroll down.














A full up message board.
BTW, do u think IBF is still tracking us?

[Byro-Nenium]

Why would they be tracking us?

[The IBF]

Cheung, There are more than 163 possible combinations under your example. There would be 162 possible pairings with racquet #1 alone.

We do not take kindly to your sort of insinuated critcisms. Accordingly, we will be declaring your equipment as non-conforming at the next tournament you enter.

Sincerely,

The International Badminton Federation

[Don]

That would come out to be 163*162 comparisons, which is a lot.

[marshall]

Read the acronym backwards :-o !

[kwun]

:lol: :lol:

[BaMBaM]

I think it would come out to more than that because a given racquet may have different versions such as Ti-10 long and Ti-10 regular, or Cab 10 or Cab 10 Tour. You get the point.

[Brett]

Don, it would be less than 163x162. For each number down the list, you would have one fewer new combination than the last racquet. Thus, for racquet #10, there would be 152 new combinations and for racquet #162, there would be only one different match. There's a button on an advanced calculator that will perform this calculation, but I haven't done this since high school and have forgotten which math function this is.

[Don]

I just realized my mistake... I forgot to take out the duplicate comparison in the permutation.

[kwun]

no. i think Don is correct. the number of combinations is 163 C 2, which is 163*162....

[Kelvin]

good one. :lol:

[Kelvin]

Look at all the trouble you've caused!!! :lol:

[Brett]

Kwun, not if you assume that the comparison of #1 vs. #163 is the same as the comparison of #163 vs. #1.

Badminton is offering us not only physical exercise but intellectual exercise too (physics for string tension arguments, math for racquet comparison calculations, etc...)

[Don]

I dug up the old arithmetic series formula and found that by eliminating a duplicate i.e. 1 vs 2 or 2 vs 1, my calculations brings it to be 13203 distinct comparisons.

[Brett]

Which, coincidentally or perhaps not, is one half of 163x162. I guess we better get to work on those comparisons. Perhaps Kwun could write a grant proposal and fund us all as his research assistants.

[kwun]

Brett.

Brett,

you're right, i did 163 P 2 instead of 163 C 2.

it has been a while since i did this... need to dig out those old math textbooks!!

anyway, this is what i remember:

a C b =

a! / ( (a-b)! * b! )

which in our case, is 163*162/2

and

a P b =

a! / (a-b)!

which is 163*162

[Don]

kwun.. you're still off the ball. It's a permutation not a combination. Order does matter, so you simpley divide by 2 to elimate the duplicate.

[kwun]

Don.

we may be talking about the same thing and i may not be clear on my last msg.

i was saying that we don't want to have permutation/ordering, thus we want 163 C 2 instead of 163 P 2. and 163 C 2 does include the divide by 2..

we don't differentiate "compare a Ti10 with MP100" and "compare a MP100 with Ti10", am i correct? :)

[Hoang Nguyen]

why bother!!! just pick one and go wack those birdies!!! hahaha...

[Cheung]

Oh no ...... o:)

[cooler]

i thought regular calculator max out at 69 factorial

[May]

good one.

[May]

teehee, who r u actually???

[May]

it's actually quite simple,just go 163+162+161+159+158.....................5+4+3+2+1= ur answer.

[May]

Any of u ever studied math????? 'Cos i don't know what the heck u guys r talking abt.

[May]

what's the model of urs????? I am not too sure abt the factorial thingie, fell asleep in class.

[Adel]

You'll learn this when you get to junior college, May... and dun worry, coz I dunno what the hell they're saying either.

[Don]

You can't compare 163 vs 163... it's 162. Plus there's a simpler way. Just multiply the permutation 163 x 162 and delete the duplicates by dividing by 2. No need to use the arithmetic series formula.

[Kelvin]

Yeah you do... lol
and give us your icq number please? :)

[cooler]

i have many models of calculators but 9.99999999e99 is the largest number allowed in all scientific calculators i know of. Only supercomputer and some main frames allow numbers > 9.99999999e99. You know how to use RPN?

nothing fancy about factorial, so don't fret over it.

[May]

thanx then.

[May]

okay, but I don't know what u r talking abt either. :(:(

[Adel]

Haven't got one at present... but am getting one soon so I can keep in touch with my parents when I go to college. Will let you ppl know in due time.

[cooler]

what grade r u in school?

[May]

huh??????

[May]

I am in sec 1, but where do u live????? There will be a difference, oh and if this helps u, I am 12.

[cooler]

where i live, grade 1 begin at age 6. Maybe your grade 1 is not the same as grade 1 in north america

[Adel]

Cooler, she's in Grade 7.

[cooler]

thanks for the correction. I mis-interpreted sec as grade. I dont know much about the education system in singapore. But i do know singaporean students are the most dedicated in studying.

[May]

:rolleyes: (Hoping this works)Yeah sure. we study only because we have to. Not that I study of course.

[Adel]

S'pore's education level vs US/Canadian equivalent:

Primary 1 to 6 = Grades 1 to 6
Secondary 1 to 4 = Grades 7 to 10
Pre-University 1 and 2 = Grades 11 and 12

Plus we do 3 years in uni for a bachelor's degree, 4 for honors, 5 for masters and 6 for doctorate/PhD... yeah, that's about it.

And like May, I wish I didn't have to study so hard =(

[cooler]

thanks adel. Yeah, the pressure to excel, especially singaporre and japan, put lots of stress to students. Academic achievement is paramount it seem. Looking back from my point of view, early school should focus less on pure academic material and more on daily living skills like 1. stress management (look at those high school shooting in the US) 2. Social behavioral skills 3. finance (as in personal budget, credit/debit system 3. Physical activity 4. etc

Oh well, the world in changing too slow for my taste. I'm getting way OT.

[Brett]

I agree with you totally, Cooler. I am a big brother in the local Big Brothers/Big Sisters program and my little brother comes from a very disadvantaged family. Although they have trouble making the rent every month, they subscribe to $50/mo digital cable for their tv. Luckily my little bro' is a great kid and I really think I can help him become a more responsible (and happy) person than anyone in his home environment.

It's too bad that schools don't focus a bit more on what it takes to be happy in life, rather than perpetuate the myth that happiness arises from slaving through one's entire life on a quest to impress everyone else with pursuit of financial gain. It's also a pitty that I didn't appreciate these concepts until I was in my early 30's.

[Adel]

I get what you mean, Brett... somebody told me on Wednesday that unless your job five years down the road can ensure that you're chauffered around in a Ferrari, you haven't got a future. I just looked at him and said, "Look, if your future is determined by a Ferrari alone, you haven't got one."

What the hell.

[kwun]

this guy has no brain or something? if i own a Ferrari, <b>I</b> myself will be driving it instead of the chauffer. i won't even let my chauffer even get near it.

he obviously has no future.

[May]

I don't study. Apart from Mother Tongue, D&T and ART(the last 2 not planning to take in sec3), I usually average a B3.

[May]

As for me, my immediate future is determined by how many distinctions I get.

[Cheung]

Hand me that Ferrari, at once! :o)

[May]

:rolleyes: Why would anybody want to give a Ferrari to u???? If u have one, u would keep it 4 urself, ryt????