## Search found 56 matches

Thu Aug 25, 2011 9:36 pm UTC
Topic: Secrets
Replies: 46
Views: 6835

### Re: Secrets

Has anyone seen "The Invention of Lying"?

It's rather interesting.
Mon Aug 08, 2011 2:08 pm UTC
Forum: Mathematics
Topic: New Scientist Enigma 1658
Replies: 8
Views: 1839

### Re: New Scientist Enigma 1658

Spoiler:
983720
.
Mon Aug 08, 2011 8:23 am UTC
Forum: Mathematics
Topic: New Scientist Enigma 1658
Replies: 8
Views: 1839

### Re: New Scientist Enigma 1658

You are not following the rules.]

Oh yeah, woops, well that's a start and thanks for the rest guys, I'll have a go at this later and see how it works out.
Sun Aug 07, 2011 11:46 pm UTC
Forum: Mathematics
Topic: New Scientist Enigma 1658
Replies: 8
Views: 1839

### New Scientist Enigma 1658

New Scientist Magazine in the UK poses a maths problem once a week called Enigma and I enjoy these, but I've come across one particularly hard one and I was wondering if someone could point me in the right direction as I'm stuck. The problem is as follows: ENIGMA is a number in which the letters den...
Thu Aug 04, 2011 8:45 pm UTC
Forum: Mathematics
Topic: Whole Number Solutions
Replies: 6
Views: 1249

### Re: Whole Number Solutions

Thanks for that Qaanol, that's dead useful.
Thu Aug 04, 2011 6:19 pm UTC
Forum: Mathematics
Topic: Whole Number Solutions
Replies: 6
Views: 1249

### Whole Number Solutions

Question, are there any whole number solutions to the equation pi(2x) - pi(x) = 0 when x > 2 ?
Thu Jul 28, 2011 10:27 am UTC
Forum: Mathematics
Topic: Prime Factorisation Running Time
Replies: 3
Views: 980

### Prime Factorisation Running Time

Just a quick question, I've been reading up on prime factorization and I'm not sure what the running time of the following algorithm is. It seems polynomial to me but obviously it's not. Could someone run me through what the running time is and why that would be fab. Thanks. :) STEP 1: Input x STEP ...
Wed Jul 20, 2011 11:09 pm UTC
Topic: 0927: "Standards"
Replies: 157
Views: 34683

### Re: 0927: "Standards"

I invoke induction.
Mon Apr 04, 2011 9:35 pm UTC
Topic: 0881: "Probability"
Replies: 326
Views: 105986

### Re: 0881: "Probability"

On xkcd Randall is God. It's his strip, his life, his art. I just wish assholes would remember that and leave it alone. Everyone needs some support sometimes, or to just get some emotion out to people they call friends, which in this case seems to be the xkcd community. I love that Randall is so ope...
Mon Mar 28, 2011 3:52 pm UTC
Forum: Mathematics
Topic: The 6 in Spearman's Rank
Replies: 2
Views: 2065

### The 6 in Spearman's Rank

Why is there a 6 in Spearman's rank?
Seriously, why the 6?
Tue Dec 28, 2010 12:21 pm UTC
Forum: Mathematics
Topic: Cardinalities
Replies: 15
Views: 1852

### Re: Cardinalities

Cheers, one quick second question. How can it be 2^aleph-null when if you think of binary integers there are aleph-null places that can be filled yet the number of integers is not 2^aleph-null?
Tue Dec 28, 2010 9:59 am UTC
Forum: Mathematics
Topic: Cardinalities
Replies: 15
Views: 1852

### Re: Cardinalities

Sorry, I worded this badly, let me try again. The function: f(x) = x/(10^ceil(log10(x))) returns a real number number between 0 and 1. z = f(x) A is the set of all possible values of z where x is a positive integer. This has a one to one correspondence with the set of all integers meaning it has a c...
Mon Dec 27, 2010 7:50 pm UTC
Forum: Mathematics
Topic: Cardinalities
Replies: 15
Views: 1852

### Re: Cardinalities

B has a cardinality of aleph null.
A is a member of set B.

It's not homework, it's just a badly developed train of thought.
Mon Dec 27, 2010 6:28 pm UTC
Forum: Mathematics
Topic: Cardinalities
Replies: 15
Views: 1852

### Cardinalities

f(x,y) = y + x/(10^ceil(log10(x)))
Where x and y are integers.

A is the set of all solutions of f(x,2).
A has cardinality Aleph null.

B is the set of all the sets of solutions to f(x,z) where z is an integer.
C is the set of all the members of all subsets of B.

What's the cardinality of C?
Sat Dec 04, 2010 10:35 pm UTC
Forum: Mathematics
Topic: Would this be a proof?
Replies: 14
Views: 1727

### Would this be a proof?

I'm still getting used to the idea of proofs and I'm just wondering would this be a proof that there are infinite Pythagorean triples? Consider that the numbers are a Pythagorean triple 3, 4 and 5. When a = 3, b = 4, c = 5 a^2 + b^2 = c^2 as 9 + 16 = 25. x is a positive integer. When x = 1 the formu...
Sun Nov 14, 2010 7:34 pm UTC
Forum: Logic Puzzles
Topic: Oranges
Replies: 3
Views: 1586

### Oranges

If all my oranges have oranges how many oranges do I have?

Spoiler:
Assuming I start with an orange and there's no multiple inheritance, infinite. If I start with 0 then I end with 0. If there's multiple inheritance then indeterminate.