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.

#1 Re: This is Cool » 0.9999....(recurring) = 1? » 2012-11-23 02:56:34

SMBoy wrote:

A = ...999

B = ...001

A + B = 1

If A was to Equal 1 on it's own then... A + B = Would Equal 1.1

First off "A + B = Would Equal 1.1" is blatantly false. A + B = 1. ...001, by your notation.

Secondly, that assumes that there is a "last digit". In your notation, the 9's clearly stop. There is a "last nine" in A, and in the same spot in B there is a corresponding 1. The problem is that this contradicts with the very definition of "infinity". If there are an infinite number of 9s, there can be no "last nine". That means that there is no corresponding location in B to put the 1, so B just becomes an infinite string of 0s. And 0.000.... (with an infinite number of 0s) = 0. So if B is 0, and A + B = 1, then A = 1.

#2 Re: This is Cool » 0.9999....(recurring) = 1? » 2008-04-14 22:55:59

Stumpe wrote:

1:

1 X 2 = 2
0.9 X 2 = 1.8
0.99 X 2 = 1.88
0.999 X 2 = 1.888 and so on and so forth, so
0.999... X 2 = 1.888...
because no matter how many 9's you add to it, you will always end up adding that many 8's .

I'd recommend checking your basic math again, before trying to attack a complicated concept like 0.999...

0.99 x 2 = 1.98, not 1.88.
0.999 x 2 = 1.998, not 1.888.
No matter how many 9's you add to it, you're not adding that many 8's, you're adding that many 9's (minus 1). So all it works out to is 1.999....8, and a difference of 0.000...2, which is the same argument as 0.999...9 and a difference of 0.000...1. Which still faces the same problem of that "infinitieth" or "last" digit of an infinitely long string of digits. And because of the definition of infinity, there is NO last digit, so the 'number' 0.000...2 = 0, because you can't have a 2 in the 'last spot', since there's always more 0s still.

#5 Re: Maths Is Fun - Suggestions and Comments » The 0.999... = 1 Fiasco » 2007-10-24 23:14:15

Wow, I'm impressed! Here is a thread complaining that there's too many 0.999... = 1 argument threads around, and you guys have managed to convert it into a 0.999... = 1 argument thread within the first 8 posts. And Anthony wasn't even around to blame! ;-)

#6 Re: This is Cool » 0.9999....(recurring) = 1? » 2007-10-23 22:42:18

Thanks for your concern for my love life. I considered finding a girlfriend, but then decided that if I did it wouldn't be fair to my wife and son. Especially since my wife is pregnant with our second child right now. I've heard that you're not supposed to get a girlfriend once you're married with a couple kids... something about "cheating".

;-)

#7 Re: This is Cool » 0.9999....(recurring) = 1? » 2007-10-23 09:22:35

Don't mind Anthony's attempted insult. He's just a little upset right now because the admin's at Wikipedia finally got so fed up with his nonsense arguments and inability to properly respond to counter arguments that they locked him out of the .999... discussion page over there. ;-)

#8 Re: This is Cool » Cut A Hole! In A Sheet Of Paper Problem!... » 2007-10-14 10:52:30

Hmm... so what does it mean that I can make a hole with an area LARGER than the starting area of the piece of paper? By careful cutting, you can actually make it so the paper unfolds and you can start with an 8.5"x11" piece of paper, and cut a hole in it that's 3'x5' (or bigger, depending on how good you are with scissors).

#9 Re: This is Cool » Domestos Kills Germs! » 2007-09-13 23:35:17

What is this thread even about at this point? Besides pointless bickering, I mean...

#10 Re: This is Cool » Domestos Kills Germs! » 2007-08-27 00:13:58

Quote: "It was the Demestos firms own TV Commercial that Stated the Quote below!
DEMESTOS KILLS 99.999 PERCENT OF ALL KNOWN GERMS"

99.999 =/= 99.999...

100 - 0.001 = 99.999
That doesn't mean that 99.999... < 1000 though, if that's the "penny" you're trying to use this argument to prove.

#11 Re: This is Cool » Domestos Kills Germs! » 2007-08-26 12:40:04

I think the confusion is that nobody really knows what the point of this post is.

All you're stating is that something doesn't kill all germs, just most. Okay... so what's the problem? That's probably just a legal thing, since if there turns out that something slips through, they can just claim that it was in the 0.001% that they don't kill and avoid getting sued.

#12 Re: This is Cool » Domestos Kills Germs! » 2007-08-23 12:19:48

No, I think that apparently I'm the one that'd be going a bit overboard... ;-)

#13 Re: This is Cool » Domestos Kills Germs! » 2007-08-23 10:36:16

It's a mathematical breakthrough! Numbers less than 100 are less than 100. Genius! ;-)

#14 Re: Help Me ! » Completing the square » 2007-07-18 02:25:36

Yeah, that's a weird question. Personally, I'd just solve it by inspection, but that probably doesn't work for a class. Since your 0x looks a bit funny, it'd probably also be acceptable to just drop it and use the following:

#15 Re: Help Me ! » Need a formula!!! or help solving » 2007-07-11 01:35:41

ppinkins wrote:

Sample question:

An employee drove from Lake Charles to a conference in Port Arthur.  A total distance from the round trip was 240 miles.  The time required to travel one way to Port Arthur was two hours.  Due to heavy traffic during the return trip to Lake Charles, an extra hour was required.  How much slower was the employee traveling on the return trip?

Start with figuring the length of each leg. Traffic doesn't change the distance, so if the round trip was 240 miles, he travelled half of that in each direction.

Then find out how fast he was travelling on the way there. Speed is simply distance divided by duration. So if you know how far he travelled to get there, and the question tells you how long it took him, you can calculate that.

To find out how fast he was travelling on the way back is much the same. You just have to do one extra calculation to determine how long it took him to get back (since the question gives you the difference in duration, but not the total new duration). Once you have the new duration, you can calculate the speed returning the same way as above.

Now, just compare the two speeds, and you'll know how much slower he travelled coming home!

#16 Re: Help Me ! » My parents and I can't agree » 2007-07-06 00:33:49

There was actually a big fuss about this recently with some phone company in the states, I was reading about it on the guy's blog. He signed up with a new phone company and they promised him that his phone would let him surf the internet for just 0.02 cents / kb. He asked them several times to clarify that they really meant 0.02 cents, and they agreed that they did. So when he used it the first month to do 3 MB of surfing, he was a bit shocked to see the bill come in at $60, instead of $6, as they'd charged him 2 cents instead of 0.02 cents. He spent a couple months arguing with customer service people, and their managers, and all sorts of people just trying to see if even if he couldn't get the charge revoked, he could at least get them to agree that 0.02 cents and 0.02 dollars (2 cents) are not the same thing. I think they finally gave him his money back, but never really admitted that they were wrong...

#17 Re: Introductions » hey » 2007-06-25 06:01:23

Welcome aboard. I haven't used Perl for several years (4-5, probably), but before that I'd used it quite extensively to program my own BBS and Chatroom entirely in Perl (this was before all the PHP boards existed). So if you want to ask any specific questions, there's always a chance that I'll remember some answers for you. ;-)

#18 Re: Puzzles and Games » Primes » 2007-06-22 05:50:56

That's not so much a "puzzle" as it is an "exercise in patience", to see who here is actually willing to take the time to continuously post numbers in a thread that could eventually get hundreds of pages long... ;-)

#19 Re: Puzzles and Games » The Battle Of Hastings. » 2007-06-22 05:48:44

Try this link: http://www.bioinfo.rpi.edu/~zukerm/cgi-bin/dq.html

Nifty program somebody wrote up to solve whatever problems you ask it.

#21 Re: Puzzles and Games » A plump and fuzzy kitten » 2007-06-22 01:21:58

John E. Franklin wrote:

And here's the sentence with all the letters, just in case 'Z' or 'Q' was missing.

Cool, thanks. Yeah, I was missing X, V, Q, J. Of course I knew which 4 symbols represented them, just couldn't match which symbol meant which letter. ;-)

#23 Re: Puzzles and Games » The Battle Of Hastings. » 2007-06-21 04:58:58

henryzz wrote:

i want solutions
are people basicly saying there r no solutions on the web

Barring the use of billions of men, I'd put forward the solution that the word "square" in this case is misused, and he merely had approximately square rectangles at his use. So even if there were an even number of men in the initial squares (12x12 = 144 per square, for example) the giant "square" had 8785 people in it, who would've been standing in a form approximates 93x93 men. But since I don't think they had helicopters, or the capacity for counting that many people at once, it would've merely seemed to be one monstrous square of people, even if it wasn't perfectly geometrically perfect. ;-)

#24 Re: Puzzles and Games » A plump and fuzzy kitten » 2007-06-21 00:38:50

So it turned out I was actually only missing two words. In the second last phrase I had the 2nd and 3rd words already, but didn't think they fit because I had the wrong 1st word so the sentence didn't make sense until I corrected the 1st word first. Then it was just a matter of solving the last word of that phrase, and my problem there turned out to be that on the top line the right yellow box appeared on my monitor to bleed into the middle box as well, so I was trying to squeeze that extra letter into the word somewhere. So once I re-examined the image and realized that there was only the 1 yellow box there, I got it all. Wahoo! Great puzzle John, thanks for that!

#25 Re: Puzzles and Games » A plump and fuzzy kitten » 2007-06-20 13:23:08

John E. Franklin wrote:

Also, 4 blocks after the the mistake 'Y'/'A', the color on the bottom is orange, though it might look like red, it's not, it's orange.
Here's some more information that may help someone whose looked at this a lot.
Purple = black + blue + yellow
Green = yellow + blue
Red = blue + black
Orange = yellow + black
Hope I'm not ruining the fun.

Yep, had noticed that it was orange and already figured what all the combo-colours mean. I think my problem with that second-last line was that I had the first word wrong, and it was throwing off my parsing of the rest of the sentence because I couldn't figure out where the noun, adjective, etc was. Now I've got the first 3 words, and will probably have the last as soon as I see the letters again (left them on a different computer), so I think I've got it all solved now. Wahoo, go me. ;-)

Board footer

Powered by FluxBB