Post whacky or neat math stuff

[Kuciwalker]

From the wiki article:



Woo.

[Ogie Oglethorpe]

Originally posted by Sir Ralph
"If one-and-a-half chickens lay one-and-a-half eggs in one-and-a-half days, how many eggs lay nine chickens in nine days?"

(That's actually pretty easy if you calculate it, but if you ask some random person to answer straight away, you hear either 9 or 81, but very rarely the true solution)

Too easy - eggs don't lay chickens.

[b etor]

they do in soviet russia.

[KrazyHorse]

By the way Kuci, you are not really a man until you have written your own MCMC routine...

[Kuciwalker]

I might have to do that next semester.

[KrazyHorse]

[Ecthy]

GEB

GGS

[Sarxis]

Originally posted by Japher
....that leaves just two people to do the work - You and Me!



And you’re just sitting there reading this! No wonder I’m tired!!!

SUCKAH!! ::flies to Hawaii::

3 guys are driving on a road trip, but need to rest for the night. They come to a Motel 6 where the sign out front says "rooms starting at $30 per night".

They decide to pull in.

At the counter, the manager rings up their bill, and the weary travellers each pay him $10.

The bellhop takes the gentlemen to their room. But because they paid their last 10 bucks for the room, they have nothing to offer as a tip to the now disgruntled bellhop.

On his way back to the front desk, the manager tells the bellhop, "I forgot that we are running our bi-monthly Motel 6 super-saver special! All rooms are only $25 tonight. Take this $5 back to our guests in room 1408."

On his way back to the room, the bellboy thinks to himself, "Those cheap bastards didn't give me even a dime for my efforts! I'm going to keep 2 bucks for myself, as that will buy me a cold one after my shift ends."

When he arrives at the cheapskate's room, he gives each of them a dollar refund, keeping back 2 of the 5 dollars due.

Each traveller paid $10 for the room, and was given back $1 for being overcharged, meaning that each only paid $9 for the room. 9 times 3 makes $27, plus the $2 the bellhop pockted makes $29. Where did the other dollar go?

[SlowwHand]

I have no idea. Some bastard is probaly retiring off my ignorance.

[Dauphin]

Originally posted by Sarxis


SUCKAH!! ::flies to Hawaii::

3 guys are driving on a road trip, but need to rest for the night. They come to a Motel 6 where the sign out front says "rooms starting at $30 per night".

They decide to pull in.

At the counter, the manager rings up their bill, and the weary travellers each pay him $10.

The bellhop takes the gentlemen to their room. But because they paid their last 10 bucks for the room, they have nothing to offer as a tip to the now disgruntled bellhop.

On his way back to the front desk, the manager tells the bellhop, "I forgot that we are running our bi-monthly Motel 6 super-saver special! All rooms are only $25 tonight. Take this $5 back to our guests in room 1408."

On his way back to the room, the bellboy thinks to himself, "Those cheap bastards didn't give me even a dime for my efforts! I'm going to keep 2 bucks for myself, as that will buy me a cold one after my shift ends."

When he arrives at the cheapskate's room, he gives each of them a dollar refund, keeping back 2 of the 5 dollars due.

Each traveller paid $10 for the room, and was given back $1 for being overcharged, meaning that each only paid $9 for the room. 9 times 3 makes $27, plus the $2 the bellhop pockted makes $29. Where did the other dollar go?

An old classic.

Double entry book-keeping would never allow for such a woeful misaddition scenario.

[Kuken]

Originally posted by Drake Tungsten

1 + 1 = a window.

Try it!

It worked!

Also, if you enter 5318008 into a calculator and then look at it upside down, it spells "boobies".

Really! Try it!

Try the same with 71349315

[Harovan]

Originally posted by Sarxis
Each traveller paid $10 for the room, and was given back $1 for being overcharged, meaning that each only paid $9 for the room. 9 times 3 makes $27, plus the $2 the bellhop pockted makes $29. Where did the other dollar go?

You counted twice for the "tip" and add numbers, that aren't supposed to be added.

The $27 paid for the room consist of $25 (which now has the manager) plus $2 (which the bellhop took as tip). You can't add the tip another time, it's already in the $27. But you can add the $3, which are in the pockets of the travellers, and which add the whole thing nicely up to the original $30.

[Seeker]

This is a little off-topic but surely someone here will know.

I'm sure they're more sophisticated these days but during the late 80s/early 90s PC computer games were often faced with the challenge of generating a 'random number'(or at least random enough), such as in a dice based game like Risk.

There were often complaints, particularly in dice-based PC games where large amounts of numbers in a short period needed to look 'random'. The old 'Axis & Allies' PC game was particularly terrible for this as over hours of play the tendency of numbers to cluster in groups and follow patterns became very noticeable, with fans making their own 'randomization' (a longer string of numbers) improvements.

1) Why did so many game makers use the PCs internal clock as the basis for their 'random' numbers?

Why not some other arbitrary number like internal cpu heat, free HD space, or whatever? Was it some kind of industry standard?

2) Is it now possible to make a truly random number, one that would be impossible to predict? Or just 'practically' impossible?

[Harovan]

Originally posted by Seeker
1) Why did so many game makers use the PCs internal clock as the basis for their 'random' numbers?

Because every PC, no matter which brand, has it.

Why not some other arbitrary number like internal cpu heat, free HD space, or whatever? Was it some kind of industry standard?

A good random number generator (e.g. for cryptography) will add more entropy, for instance the numbers you named (if available), time intervals between key strokes, mouse moves and alike.

EDIT (example): If you install TrueCrypt and initialize a partition on your HDD, you're asked to move your mouse over the dialogbox for at least a minute - for exactly that reason.

2) Is it now possible to make a truly random number, one that would be impossible to predict? Or just 'practically' impossible?

Impossible. Even the best numerical algorithm will give only pseudo-random numbers, i.e. numbers that look random and are distributed like random numbers, but are predictable, if you have the formula.

But as far as I know there are hardware devices that can give truly random numbers.

[Kuciwalker]

Impossible. Even the best numerical algorithm will give only pseudo-random numbers, i.e. numbers that look random and are distributed like random numbers, but are predictable, if you have the formula.

But as far as I know there are hardware devices that can give truly random numbers.

Eh, why the distinction? Any software running on a quantum computer can generate random numbers.