## Search found 291 matches

- Sat Nov 21, 2009 6:02 pm UTC
- Forum: Mathematics
- Topic: Help with probability problems please .....
- Replies:
**9** - Views:
**1365**

### Help with probability problems please .....

Okay it's aaaaages since I was at school (even the abacus wasn't invented :shock: ), so my maths is a lil' rusty to say the least. I'm trying my hand at some puzzles online and I'm having problems with some probability ones: 1. There are 6 people in a room. Each person randomly chooses a positive in...

- Mon Nov 02, 2009 9:19 pm UTC
- Forum: Logic Puzzles
- Topic: Tetris Strategy
- Replies:
**15** - Views:
**6225**

### Re: Tetris Strategy

Szech wrote:Couldn't get over 8. Someone ask this guy to try -- http://www.youtube.com/watch?v=jwC544Z37qo

That can't be real ..... can it ?????

- Tue Oct 20, 2009 7:31 pm UTC
- Forum: The Help Desk
- Topic: Windows Media Player not reading CD data
- Replies:
**7** - Views:
**1247**

### Re: Windows Media Player not reading CD data

Thanks for the help - I suppose all I can do is wait until the data is updated on the net. Or you could type it in yourself... Yea I've already done that :? - but has anyone any idea how I find which data base Windows Media Player uses. I know that it's possible to go onto the site and correct any ...

- Sun Oct 18, 2009 11:37 am UTC
- Forum: The Help Desk
- Topic: Windows Media Player not reading CD data
- Replies:
**7** - Views:
**1247**

### Re: Windows Media Player not reading CD data

Just outta curiosity - how do I find out which data base WMP is using - it's just that one of the CD's that I ripped, has got the completely wrong picture for the cover. I'm just wondering if it's possible to contact them and inform them of the error so that it can be corrected .

- Sat Oct 17, 2009 8:34 pm UTC
- Forum: The Help Desk
- Topic: Windows Media Player not reading CD data
- Replies:
**7** - Views:
**1247**

### Re: Windows Media Player not reading CD data

Ahh I see, so the problem is prob 'cos it's a new CD (I think it was released on Mon 12th Oct). .... so I'm assuming there's prob no info out yet for this CD, which is why WMP can't find it :oops: . I asked my m8 if the info was stored on the CD, or if it was retrieved from somewhere on the net - I ...

- Sat Oct 17, 2009 8:09 pm UTC
- Forum: The Help Desk
- Topic: Windows Media Player not reading CD data
- Replies:
**7** - Views:
**1247**

### Windows Media Player not reading CD data

I got a new CD a few days ago, played it on my PC earlier and I noticed that it won't read the track details etc. I tried a few different CD's and after a few seconds it comes up with the album title, album cover artwork and all the individual track listings - it's just this 1 CD it won't read. It p...

- Wed Sep 30, 2009 10:48 pm UTC
- Forum: Logic Puzzles
- Topic: Help with Youthful precocity from Amusements in Mathematics
- Replies:
**2** - Views:
**1411**

### Re: Help with Youthful precocity from Amusements in Mathematics

Your solution yields a value for B which is not an integer because you're mixing old currency and new currency (pre and post decimalisation). If you're working it out using the old currency, then you are correct in saying that a sixpence is 6p, but a fiver is not 500p - there was 240...

- Tue Sep 29, 2009 10:25 am UTC
- Forum: Logic Puzzles
- Topic: Time Stop Chess
- Replies:
**9** - Views:
**2940**

### Re: Time Stop Chess

Actually letting you control black changes the puzzle significantly. For example it's definitely possible to checkmate in 3 moves if you control their moves Plus, if you turn the tables - black can mate white in 2 moves (I think every seasoned chess player knows "Fools's Mate") f2-f4 e7-e...

- Tue Sep 29, 2009 10:07 am UTC
- Forum: Logic Puzzles
- Topic: Time Stop Chess
- Replies:
**9** - Views:
**2940**

### Re: Time Stop Chess

para-prophet wrote:every chess players knows that the blacks king pawn is the only pawn defend by only the king

I take it you mean "black's king's bishops's pawn" (pawn on F7) ??

Your wording suggests it's the pawn on E7 - which is clearly wrong .

- Sat Sep 26, 2009 11:53 am UTC
- Forum: Logic Puzzles
- Topic: Sum and Product (variant)
- Replies:
**2** - Views:
**1147**

### Re: Sum and Product (variant)

I also think the puzzle is wrong. The only such sum is 11. P will deduce this, regardless of which product he has (could be 18, 24, 28, or 30). When P says he now knows the sum, this just tells S what he already knew. There is no way S can pick out the correct product out of the four possib...

- Fri Sep 25, 2009 6:10 pm UTC
- Forum: Logic Puzzles
- Topic: Sum and Product (variant)
- Replies:
**2** - Views:
**1147**

### Sum and Product (variant)

Original puzzle: http://forums.xkcd.com/viewtopic.php?f=3&t=131&p=1433081&hilit=product+sum#p1433081 This one is worded differently and is taken from http://www.projecteureka.org/ In my opinion this puzzle (or at least, the answer that it gives) is incorrect - but I'll see what you lot c...

- Mon Sep 21, 2009 8:51 pm UTC
- Forum: Logic Puzzles
- Topic: Tetris Strategy
- Replies:
**15** - Views:
**6225**

### Re: Tetris Strategy

Thanks for the link - I used to love playing Tetris. I also played a version called Tetren, where the higher levels have blocks already in place, some of them moving and poss some indestructable .... can't quite remember as it was a LONG time ago .... used to play it on an Amiga :oops: Anyway - just...

- Fri Sep 18, 2009 4:59 pm UTC
- Forum: Logic Puzzles
- Topic: Urns and Marbles
- Replies:
**3** - Views:
**1252**

### Re: Urns and Marbles

Thanks for that guys - I was assuming (incorrectly) that I had to

**Spoiler:**

- Fri Sep 18, 2009 10:55 am UTC
- Forum: Logic Puzzles
- Topic: Urns and Marbles
- Replies:
**3** - Views:
**1252**

### Urns and Marbles

Okay, I gotta admit - I'm at a loss with this one .... I'm posting this as I don't have a clue what the answer is, But I'm sure you lot will solve it. Here's the problem: You are presented with two urns and 10 red marbles and 10 white marbles. You may place the marbles in the urns as you please (you...

- Wed Sep 16, 2009 6:23 pm UTC
- Forum: Logic Puzzles
- Topic: Three Princesses with random middle sister
- Replies:
**9** - Views:
**2295**

### Re: Three Princesses with random middle sister

So what exactly is the question ?? Are we simply trying to avoid marrying the middle sister (if so, it's been done before) ?? ...... or do you want to be able to actually identify which one is the middle sister ?? Even though her choice is determined by the flip of a coin - she could (in theory) end...

- Tue Sep 15, 2009 7:42 pm UTC
- Forum: Logic Puzzles
- Topic: Three princesses
- Replies:
**446** - Views:
**205384**

### Re: Three princesses

Has this been answered yet? I think I have the answer, skimmed through, but didn't see it. Let me know if this will work. Ask All Three if they are the middle sister The oldest one will say No The Youngest one will say Yes You don't know what the middle sister will say yet. If you get two Yes&#...

- Sun Sep 06, 2009 1:00 pm UTC
- Forum: Logic Puzzles
- Topic: Nice easy one .........................
- Replies:
**15** - Views:
**2269**

### Re: Nice easy one .........................

I feel better now that a few people got it wrong, 'cos I also got this wrong initially.

Just for the record, the problem is from:

http://www.projecteureka.org/problem/question/561

Just for the record, the problem is from:

http://www.projecteureka.org/problem/question/561

- Sat Sep 05, 2009 12:13 pm UTC
- Forum: Logic Puzzles
- Topic: Nice easy one .........................
- Replies:
**15** - Views:
**2269**

### Re: Nice easy one .........................

jaap wrote:Spoiler:

spoilsport

If you wanna try this - don't look at any spoilers ...... I was hoping to fool someone with this one .

- Sat Sep 05, 2009 11:26 am UTC
- Forum: Logic Puzzles
- Topic: Nice easy one .........................
- Replies:
**15** - Views:
**2269**

### Nice easy one .........................

In the figure below, the radius of circle A is 2 units, the radius of circle B is 3 units. Starting from the position shown in the figure, circle A rolls around circle B (circle B remains stationary). At the end of how many revolutions of circle A, will the centre of circle A first reach its startin...

- Mon Aug 24, 2009 8:06 pm UTC
- Forum: Logic Puzzles
- Topic: Number Sequence .............
- Replies:
**2** - Views:
**999**

### Re: Number Sequence .............

Penitent87 wrote:Looks to me like the lowest prime divisor of the numbers starting from 1999, at a glance.

That should enable you to work out the next.

It certainly did - thanks for the help

- Mon Aug 24, 2009 3:56 pm UTC
- Forum: Logic Puzzles
- Topic: Number Sequence .............
- Replies:
**2** - Views:
**999**

### Number Sequence .............

I'm usually OK at number sequences, but I've gotta admit that I can't figure this one out ....

What is the next number in the following sequence ???

1999, 2, 3, 2, 2003, 2, 5, 2, 3, 2, ...

What is the next number in the following sequence ???

1999, 2, 3, 2, 2003, 2, 5, 2, 3, 2, ...

- Wed Aug 19, 2009 6:01 pm UTC
- Forum: Logic Puzzles
- Topic: brain in a vat
- Replies:
**214** - Views:
**26297**

### Re: brain in a vat

Puck wrote:I think you've just given an example of what doesn't work. Your example (though fictional) would demonstrate that artificial constructs are capable of responses which appear human.

Yea but:

**Spoiler:**

- Wed Aug 19, 2009 5:46 pm UTC
- Forum: Logic Puzzles
- Topic: brain in a vat
- Replies:
**214** - Views:
**26297**

### Re: brain in a vat

This reminds me of a film from 1986, that I'm surprised no-one has mentioned: Has no-one seen the film Short Circuit ?? There's a scene in there, where someone is trying to determine whether the "robot" in the film is actually "alive". They slap some paint onto a piece of pap...

- Sun Jul 26, 2009 8:42 pm UTC
- Forum: Logic Puzzles
- Topic: Alphabet
- Replies:
**15** - Views:
**2303**

### Re: Alphabet

Another one: 1. BCDGIJLMNOPQRSUVWZ 2. AEFHKTXY The following kinda works (a bit dodgy on 1 or 2 of them): The letters in number 1, can all be hand-written without taking your pen off the paper; whereas the letters in number 2 usually require the pen to come off the paper (if written normally...

- Mon Jul 13, 2009 8:17 pm UTC
- Forum: Logic Puzzles
- Topic: a riddle
- Replies:
**20** - Views:
**7567**

### Re: a riddle

twin brothers, born in march but had their birthdays in april. They were born in a place called March, sometime in the month of April. one was 20 and the other was 22 Well, you haven't said what the numbers 20 and 22 refer to, so it could be that one of them weighs 20 stone; the other a lil'...

- Mon Jun 22, 2009 11:29 pm UTC
- Forum: Logic Puzzles
- Topic: Aliens and candybars...
- Replies:
**14** - Views:
**1615**

### Re: Aliens and candybars...

Dividing this pile equally between the 6 aliens and leaving only 1 for the human gives: {15625 x Q / 46656 - 155155 / 46656} / 6 = [6 x N] + 1 You have an extra "/ 6" there. Post edited acordingly. I think it tallies with your solution now: [15625 x Q] = [279936 x N] + 201811 If Q = 27993...

- Mon Jun 22, 2009 10:23 pm UTC
- Forum: Logic Puzzles
- Topic: Aliens and candybars...
- Replies:
**14** - Views:
**1615**

### Re: Aliens and candybars...

Dunno if my maths is correct - but I'll go through what I've got so far: If Q is amount of candybars in initial pile, then after the 6th alien takes his 1/6 share, the amount left in the pile is: 5/6 x {5/6 x [5/6 x {5/6 x [5/6 x {5/6 [Q - 1] -1} -1] -1} -1] -1} = 15625 x Q / 46656 - 155155 / 46656 ...

- Mon Jun 22, 2009 9:11 pm UTC
- Forum: Logic Puzzles
- Topic: Aliens and candybars...
- Replies:
**14** - Views:
**1615**

### Re: Aliens and candybars...

I haven't had time to look at this puzzle properly yet but I think Goplat's solution is incorrect :? . The puzzle states that the alien gives a candybar to the human being first and then takes 1/6 of the remaining candybars for himself. In Goplat's solution, the alien takes 1/6 for himself first and...

- Mon Jun 22, 2009 7:32 pm UTC
- Forum: Logic Puzzles
- Topic: Spider
- Replies:
**23** - Views:
**7354**

### Re: Spider

I emailed them yesterday telling them how lame I though the answer was. Got a reply today: Hi James, I knew right from the beginning that there are multiple solutions, you forgot also about Koala Bear (technically not a bear). I will rephrase the problem ;-), I think Pandas are the only vegetarian b...

- Sun Jun 21, 2009 7:53 pm UTC
- Forum: Logic Puzzles
- Topic: Spider
- Replies:
**23** - Views:
**7354**

### Re: Spider

skeptical scientist wrote:Aw, I think that answer is kind of lame.

Ditto.

- Sun Jun 21, 2009 6:49 pm UTC
- Forum: Logic Puzzles
- Topic: Spider
- Replies:
**23** - Views:
**7354**

### Re: Spider

Well, the answer isn't:

**Spoiler:**

- Sun Jun 21, 2009 6:22 pm UTC
- Forum: Logic Puzzles
- Topic: Spider
- Replies:
**23** - Views:
**7354**

### Re: Spider

Bravemuta wrote:Spoiler:

Well:

**Spoiler:**

- Sun Jun 21, 2009 5:31 pm UTC
- Forum: Logic Puzzles
- Topic: Spider
- Replies:
**23** - Views:
**7354**

### Re: Spider

Well, is there a bear that can... jump 1.25 meters in the air? Or one that's likely to fall out of a low tree? I keep thinking up something, only to come on here and find that someone has beat me to it. I also worked out that: If the bear falls in the hole from a distance of 1.25m above the hol...

- Sun Jun 21, 2009 4:50 pm UTC
- Forum: Logic Puzzles
- Topic: Spider
- Replies:
**23** - Views:
**7354**

### Re: Spider

Concerning the bear: This is a rather stab-worthy question because The time is measure from when the bear enters the hole. so, It's not the gravitational acceleration that is different from what you'd expect. The bear is on Planet Earth. Now, if the acceleration is 1g, what else ca must be ...

- Sun Jun 21, 2009 11:26 am UTC
- Forum: Logic Puzzles
- Topic: Spider
- Replies:
**23** - Views:
**7354**

### Re: Spider

Yat wrote: If you give me a clue about the bear, I give you a clue about the spider !

I'm also stuck on the bear - I haven't got a clue what it's going on about !!!

By the way - what number is the spider puzzle - I can't seem to find it .

- Thu Jun 18, 2009 7:25 pm UTC
- Forum: Logic Puzzles
- Topic: Crazy food
- Replies:
**4** - Views:
**1357**

### Re: Crazy food

**Spoiler:**

- Thu Jun 11, 2009 9:33 pm UTC
- Forum: Logic Puzzles
- Topic: How many different pairs ???
- Replies:
**3** - Views:
**920**

### Re: How many different pairs ???

What is this, an AMC 10 problem? It's a problem I stumbled across on a forum somewhere, that I failed to solve because of a very simple error: I got down to ab 2 = a 2 b, but I made the fatal mistake of dividing both sides by ab and ended up with just a = b As you can see my maths is kinda rusty - ...

- Wed Jun 10, 2009 10:03 pm UTC
- Forum: Logic Puzzles
- Topic: How many different pairs ???
- Replies:
**3** - Views:
**920**

### How many different pairs ???

In general (a - b)

However, for some values of a and b, we indeed have:

(a - b)

If we assume 0 ≤ a ≤ 2009, 0 ≤ b ≤ 2009 and both are integers, how many different pairs of such (a, b) satisfy (a - b)

^{3}≠ a^{3}- b^{3}.However, for some values of a and b, we indeed have:

(a - b)

^{3}= a^{3}- b^{3}.If we assume 0 ≤ a ≤ 2009, 0 ≤ b ≤ 2009 and both are integers, how many different pairs of such (a, b) satisfy (a - b)

^{3}= a^{3}- b^{3}?- Sun Jun 07, 2009 10:02 pm UTC
- Forum: Logic Puzzles
- Topic: How many zeros ????
- Replies:
**10** - Views:
**3918**

### Re: How many zeros ????

horisustar wrote:... There are two zeros in the number 100. And I suppose an infinate number after a decimal point.

I think you missed the !

The question asked "How many zeros are there at the end of 100! ????" (Note the ! - denoting "factorial").

- Sun Jun 07, 2009 9:44 pm UTC
- Forum: Logic Puzzles
- Topic: How many zeros ????
- Replies:
**10** - Views:
**3918**

### How many zeros ????

I wasn't sure whether to post this in maths, or in here, so ..... well, it's here now (unless a mod decides to move it ).

Consider the number 100!

How many zeros are there at the end of 100! ????

Consider the number 100!

How many zeros are there at the end of 100! ????