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

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#1 Re: Help Me ! » Imposible Question » 2007-06-17 14:47:15

0/0 seems invalid to me . 0 can't be the denumerator .that's the rule.

#3 Re: Help Me ! » Questions » 2007-06-02 09:13:53

To Jane question
    I haven't learn Fermat's little theorem thought , there is way to do it

Is group helpful on this one?

#5 Re: Exercises » Jane’s exercises » 2007-06-01 20:01:07

Yah , it comes from mutiplication law of mod

#7 Re: Help Me ! » can someone check+ stats! » 2007-06-01 07:27:58

Skiing: 0.40
Skating: 0.55
Racquet sports: 0.35
These are not pure Skiing , skating and Racquet? OH , Nevermind.then,

#9 Re: Help Me ! » can someone check+ stats! » 2007-05-31 19:05:02

I got the same answer as you did on the first one

the second one , however   I got 13/18
Four player throw dices, the result can be listed

_ _ _ _  (each blank can be filled in with 1,2,3,4,5,6)
Let's consider the counter situation
the first blank can take value from 1 to 6 , ( choose 1 from 6)
Since the second blank must be different ,there only 5 choice ( choose 1 from 5)
So on...
and the number of arrangement that four players roll different number  is  6x5x4x3
the probability of four players roll different number will be  (6x5x4x3)/(6x6x6x6)
then , at least two ppl roll the same number will be  1- (6x5x4x3)/(6x6x6x6)

#10 Re: Dark Discussions at Cafe Infinity » Global Warming- It's Happening! » 2007-05-30 03:07:50

Look at the climate change in China , Very convincing example of Global warming.

#11 Re: Dark Discussions at Cafe Infinity » Long words! » 2007-05-30 03:05:23

The longest Ive learned is "electroencephalogram"

#12 Re: Help Me ! » Help me with thi... » 2007-05-29 19:24:07

The only clue I have is
Since A,B,C,D are distinct , and primes can't be divides by 2, or 5.
A,B,C,D={1,3,7,9},A+B+C+D=20
S=(2A+2B)1000+(A+2D+C)100+(A+2D+C)10+(A+B+C+D)=2000(A+B)+(A+2D+C)110+20

#13 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-28 13:24:58

If the density of a matter is higher than it's entourage , there will be pressure , making it have the tendency of distributing its matter evenly .  If a ballon placed in a void , I think it will explode.. And the universe's expand is pretty much the same..I guess.

#14 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-27 18:19:12

but I think  space wont just be a void ?  My point is maybe the speed of the departing planets isnt enough represent the speed of the universe.

#15 Re: Dark Discussions at Cafe Infinity » So The Season of LOST Has Ended ... [ LOST Discussion Thread ] » 2007-05-27 08:05:33

I thought it's very attractive with those mysterious number and alien things , but turned out that wasnt the point ..disappointed.

#16 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-27 08:02:32

Consider this , A quantity of water placed in a dam , and there are some solids objects floating a the in water(in not on) , when the dam breaks , the displacement of water in certain time is greater than those of the objects.  Maybe the universe structure is like darkmatter as water and planets like the object floating in it.

#18 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-25 07:57:13

Daniel123 wrote:

If the universe is expanding, what happens when you get to the edge of it? And i dont see how it can be both infinite and expanding - because if it was expanding, there must be and edge that is expanding, but if it was infinite then there would be universe already beyond that edge. Does anyone understand what i mean?

Got a simply answer , the universe is infinite because it's expanding.  Expanding

infinite.

#19 Re: Help Me ! » Diff Eq. Confusion » 2007-05-24 14:13:47

But I have no idea on the second one.

#20 Re: Help Me ! » Coordinate Geometry: Distance between Parallel Lines » 2007-05-24 14:12:37

U can use the formula

I got a very elementary method .

#21 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-24 10:18:15

My situation is kinda different , I've been in USA for 5 month by now, I have to prepare for SAT .
I really love math thought I am not very good at it.

This seems kinda oof topic , let's get back to it

#23 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-24 09:59:59

Maybe the word end has extra abstract concept when applying to the universe.

#24 Re: Dark Discussions at Cafe Infinity » What shape is the universe? » 2007-05-24 09:52:46

I can give an example of inifinite and expanding ,  like the interval (1,2) , you can never reach the end of it , thought you are moving toward 2 , but the interval can expand to (0 ,3) .... haha~

#25 Re: Dark Discussions at Cafe Infinity » Haikus » 2007-05-24 09:40:59

In the void of death
Hollow outstrips conciousness
All become surreal.

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