## Search found 115 matches

Mon Dec 17, 2007 6:56 am UTC
Forum: Logic Puzzles
Topic: Simple Math Puzzle
Replies: 3
Views: 2225

### Re: Simple Math Puzzle

Spoiler:

Code: Select all

`8 /(4 x 2)= 1-   -   +7 + 9 + 6 = 22+   x   /5 + 1 - 3 = 3=   =   =6  -5   4`
Sun Dec 16, 2007 6:00 am UTC
Forum: Mathematics
Topic: How would you simplify this
Replies: 24
Views: 2248

### Re: How would you simplify this

Done it. It's a very elegant problem.
xprisoner wrote:Q: How would I simplify this?

A: Software (Maple)
Also, this. It's very useful to know the answer before you start something like this.
Thu Dec 06, 2007 4:43 am UTC
Forum: Forum Games
Topic: Onslaught
Replies: 34
Views: 5769

### Re: Onslaught

New high score: 350,827,684,880.

Laser chains are the only way to get high scores, they are ridiculously more powerful than nukes.
Thu Dec 06, 2007 2:06 am UTC
Forum: Logic Puzzles
Topic: Small values of 20
Replies: 42
Views: 5635

### Re: Small values of 20

Spoiler:
For small values of 20
Wed Dec 05, 2007 12:09 pm UTC
Forum: Mathematics
Topic: Project Euler 20
Replies: 22
Views: 7761

### Re: Project Euler 20

This is a plot of f(n) divided by jestingrabbit's formula for the number of digits minus the number of trailing zeros. As expected, it converges to 4.5.
fnoverndigits.JPG (24.42 KiB) Viewed 8903 times

(I took an average of the upper and lower estimates, but it makes no difference when n is large enough)
Thu Nov 15, 2007 3:26 am UTC
Forum: Mathematics
Topic: Multiplying pi to get whole numbers
Replies: 41
Views: 13965

### Re: Multiplying pi to get whole numbers

If you ask google to multiply any 8 digit number greater than about 70,000,000 by pi and divide it by 2, you always get an integer. It only displays 9 significant figures.
Tue Nov 13, 2007 5:21 am UTC
Forum: Logic Puzzles
Topic: Sudoku Math Puzzle
Replies: 8
Views: 2669

### Re: Sudoku Math Puzzle

Spoiler:
148
726
593

Determinant = 412, this is the maximum for a 3x3 box.

(should this be spoilerised?) yes
Tue Oct 30, 2007 6:42 am UTC
Topic: A line inside a square
Replies: 62
Views: 7594

### Re: A line inside a square

This is fun! I've been doodling in square 6.4.
Fri Oct 26, 2007 6:18 am UTC
Forum: Logic Puzzles
Topic: The length of a river [solved]
Replies: 8
Views: 2566

### Re: The length of a river [unsolved]

I much prefer the geometric solution, myself. twoboats.JPG The vertical axis is distance, where A and D are the two stations. The horizontal axis is time. The blue and red lines are the paths of the boats, intersecting at P1 and P2 (I left out the 20 minute stops because they don't change th...
Wed Oct 24, 2007 4:36 am UTC
Forum: Logic Puzzles
Topic: Separation of Numbers
Replies: 10
Views: 2060

### Re: Separation of Numbers

Obviously, a solution to the first problem would lead quickly to a solution for this one, just by taking the list, making a copy, reversing the digits in each element of the copy, and appending the copy to the original list. You don't need a full solution to be able to do this. Just take one of...
Tue Oct 23, 2007 11:00 am UTC
Forum: Logic Puzzles
Topic: Separation of Numbers
Replies: 10
Views: 2060

### Re: Separation of Numbers

Spoiler:
There are no solutions.

Am I right, or is my code broken?
Sat Oct 13, 2007 11:45 am UTC
Forum: Logic Puzzles
Topic: interesting magic square
Replies: 11
Views: 2685

### Re: interesting magic square

I wrote a backtracking algorithm in c++ to find them. These are the first few magic squares it spat out: 127888 265678 778345 873754 856663 875446 127888 265678 778354 873745 856663 875446 127888 265678 778354 873754 855664 876436 127888 265678 867346 884743 856573 775546 127888 265678 867355 873844...
Sat Oct 13, 2007 5:39 am UTC
Forum: Logic Puzzles
Topic: Tip of the hat
Replies: 7
Views: 2450

### Re: Tip of the hat

This has been posted before, here. The solution: 19 can survive. The prisoner at the back counts how many white hats he can see. If it is odd, he says white. The next prisoner can then work out the colour of his hat by counting how many white hats he can see and comparing that with what the prisoner...
Fri Oct 12, 2007 1:16 am UTC
Forum: Logic Puzzles
Topic: Maths is broken Mk II
Replies: 6
Views: 2807

### Re: Maths is broken Mk II

Spoiler:
D is actually on the other side of GC.
Tue Oct 09, 2007 11:38 am UTC
Forum: Logic Puzzles
Topic: Lockbox Mk. II solution thread
Replies: 68
Views: 6641

### Re: Lockbox Mk. II solution thread

DrStalker wrote:Romeo gets in a box, with the ring and a weeks supply of food and water.

He posts himself to Juliet.

The post office can't fail to deliver the box without Romeo knowing.

Romeo and Juliet are indefinitely grounded inside their homes
Tue Oct 09, 2007 11:16 am UTC
Forum: Logic Puzzles
Topic: Lockbox Mk. II solution thread
Replies: 68
Views: 6641

### Re: Lockbox Mk. II solution thread

Assuming that Romeo knows exactly where Juliet lives, and has access to some modern technology, he could just put a GPS tracking device with the ring in the locked box from the original solution. As long as he tells the postal service, they will have to deliver it.
Wed Sep 12, 2007 8:04 am UTC
Forum: Logic Puzzles
Topic: Introductory Riddlage
Replies: 27
Views: 5950
E: The red-haired man... both the travellers have red hair, and one has black clothes or something else? The question still makes sense if we assume the tavernkeeper has black hair.
Tue Sep 11, 2007 1:47 pm UTC
Forum: Forum Games
Replies: 17221
Views: 1701511
I get 1:27, total 11:23
Mon Sep 10, 2007 5:13 am UTC
Topic: 0314: "Dating Pools"
Replies: 214
Views: 106188
What? Not even a mention of pi? I'm disappointed.
Sun Sep 09, 2007 9:37 am UTC
Forum: Forum Games
Replies: 17221
Views: 1701511
1:35, total 9:56
Sat Sep 08, 2007 10:11 am UTC
Forum: Forum Games
Replies: 147
Views: 16189
I get... 3:09.
That puts me on 8:21
That's the biggest gap so far, I think.
Fri Sep 07, 2007 7:43 am UTC
Forum: Forum Games
Replies: 147
Views: 16189
No one's posting? I'll take the 65 then.

5:12
Fri Sep 07, 2007 6:38 am UTC
Forum: Forum Games
Replies: 147
Views: 16189
I get... 42.

4:07
Fri Sep 07, 2007 4:13 am UTC
Forum: Forum Games
Replies: 147
Views: 16189
I get points... 43 of them. Total 3:25
Fri Sep 07, 2007 3:17 am UTC
Forum: Forum Games
Replies: 147
Views: 16189
23 minutes to 2:42
Fri Sep 07, 2007 1:47 am UTC
Forum: Forum Games
Replies: 147
Views: 16189
Another 36. That puts me on 2:19
Thu Sep 06, 2007 12:00 pm UTC
Forum: General
Topic: I have no idea what the point is . . . But I want one
Replies: 40
Views: 4257
Maurog wrote:Why is 1 using only two nines? If you make a clock where every digit is three nines, do it right.

Isn't it (9/9)^9 ? That's why there are brackets.
Thu Sep 06, 2007 10:15 am UTC
Forum: Forum Games
Replies: 147
Views: 16189
23 minutes. That makes 103 total. Broke 100, yay!
Thu Sep 06, 2007 9:28 am UTC
Forum: General
Topic: I have no idea what the point is . . . But I want one
Replies: 40
Views: 4257
CorranH wrote:EDIT - Oh god. I didn't notice at first glance. Let the arguments reign . . .
What didn't you notice at first glance?

I'm thinking it was the .999... That always generates arguments. But what is the crappy pun?
Thu Sep 06, 2007 7:58 am UTC
Forum: Logic Puzzles
Topic: Easy one for people with quantum computers
Replies: 17
Views: 3659
I factored the number in GAP using the FactInt package. You can set it to tell you what steps it is taking. It starts out by checking whether n=b^k +- 1, so it immediately found the twin prime factors. (It then checks all primes <1000, then moves on to more complicated algorithms)
Thu Sep 06, 2007 7:41 am UTC
Forum: Forum Games
Replies: 147
Views: 16189
Another 55 minutes for me. That makes 80
Thu Sep 06, 2007 6:41 am UTC
Forum: Forum Games
Replies: 147
Views: 16189
25 minutes for me
Thu Sep 06, 2007 4:28 am UTC
Forum: Logic Puzzles
Topic: Easy one for people with quantum computers
Replies: 17
Views: 3659
200 digits still takes a while, in general. But your two primes were twin primes, which made it very quick to factorise.
Thu Sep 06, 2007 3:27 am UTC
Forum: Logic Puzzles
Topic: Easy one for people with quantum computers
Replies: 17
Views: 3659
Come on... at least make the numbers big enough so they require a quantum computer to factorise!
Wed Sep 05, 2007 2:28 am UTC
Forum: Science
Topic: Laser-wielding cyborg fairyflies.
Replies: 32
Views: 8396
I had to laugh at this:

Isao Shimoyama wrote:We had an incident last week where we sent a roach into an duct to test for an air leak, when we asked the roach to turn right, it responded by asking for our email addresses and offered to send us viagra in return.
Tue Sep 04, 2007 12:42 pm UTC
Forum: Food
Topic: Microwave Recipes
Replies: 61
Views: 9325
I would recommend one of these. They are great for cooking meat in a microwave, as well as many other things.
Mon Sep 03, 2007 10:57 am UTC
Forum: General
Topic: What is in Your Garage?
Replies: 45
Views: 5521
There is so much stuff in my garage that the car *doesn't* fit. It has been parked in the driveway for about the last month.
Mon Sep 03, 2007 10:38 am UTC
Forum: General
Topic: Confessional Shed - I'll keep a look-out
Replies: 38049
Views: 2813366
Confession: I can no longer see the floor of my bedroom. Except underneath my chair, but that doesn't count.
Sat Sep 01, 2007 1:06 am UTC
Forum: Logic Puzzles
Topic: Easy one for people with quantum computers
Replies: 17
Views: 3659
solution wrote:Wait... this number has a small factor. It's divisible by 101. The answer is 7.
I'm not sure how to do it without factorising it, though.
EDIT: although knowing that 101 is a factor you can find the answer from what Cauchy wrote.
Fri Aug 10, 2007 11:37 am UTC
Forum: News & Articles
Topic: Timewavezero clip
Replies: 2
Views: 1371
I wonder if he understood any of that himself? Because I certainly didn't.