prime number link

gollumprawn

it's mine

General

21 May 06 23:28

Bowmann

Non-Subscriber

RHP IQ

Joined: 17 Mar 05
Moves: 1345

27 May 06 13:56

Bowmann Prime Number Fact

There is always a prime number between any given number and its double.

Sicilian Smaug

Joined: 15 Aug 05
Moves: 96595

27 May 06 13:58

This post is unavailable

Please refer to our posting guidelines

Sicilian Smaug

Joined: 15 Aug 05
Moves: 96595

27 May 06 13:58

This post is unavailable

Please refer to our posting guidelines

Derfel Cadarn

The Mighty

Rocky Mountains

Joined: 20 Aug 05
Moves: 17145

27 May 06 14:00

Originally posted by Bowmann
[b]Bowmann Prime Number Fact

There is always a prime number between any given number and its double.[/b]

Derfel Pime Number Fact

Any number that individually adds up to be a divisible of three can be divided by three.

Example: 2571

2+5+7+1=15

Not prime.

Bowmann

Non-Subscriber

RHP IQ

Joined: 17 Mar 05
Moves: 1345

27 May 06 14:03

Originally posted by Derfel Cadarn
Derfel Pime Number Fact

Any number that individually adds up to be a divisible of three can be divided by three.

Example: 2571

2+5+7+1=15

Not prime.

Pathetic. Nothing whatsoever to do with primes.

Derfel Cadarn

The Mighty

Rocky Mountains

Joined: 20 Aug 05
Moves: 17145

27 May 06 14:05

Originally posted by Bowmann
Pathetic. Nothing whatsoever to do with primes.

Sure it does. Easy way to rule out being divisible by 3.

Phlabibit

Mystic Meg

tinyurl.com/3sbbwd4

Joined: 27 Mar 03
Moves: 17242

27 May 06 16:13

1 edit

Originally posted by Derfel Cadarn
Sure it does. Easy way to rule out being divisible by 3.

So you are just saying any given number, if it adds to 15 is not prime?

113

P-

Nordlys

The sky

Joined: 05 Apr 05
Moves: 10385

27 May 06 16:18

1 edit

Originally posted by Phlabibit
So you are just saying any given number, if it adds to 15 is not prime?

If "it adds up to 15" means "the sum of its digits is 15", yes.

Edit: Oops, I just saw the "just" in your post. He is saying that any given number whose digits add up to a number which is a multiple of 3 is divisible by 3 and thus not a prime, unless the number is 3 itself.

Bowmann

Non-Subscriber

RHP IQ

Joined: 17 Mar 05
Moves: 1345

27 May 06 16:23

Bowmann Prime Number Fact

3 is the only prime that is one less than a perfect square.

badbadger

Joined: 18 Apr 06
Moves: 2443

28 May 06 00:59

Originally posted by Bowmann
[b]Bowmann Prime Number Fact

3 is the only prime that is one less than a perfect square.[/b]

square do you mean square root?
because 143 is a prime number (one less than 144, the square root of 12)

badbadger

Joined: 18 Apr 06
Moves: 2443

28 May 06 01:00

Originally posted by Bowmann
[b]Bowmann Prime Number Fact

There is always a prime number between any given number and its double.[/b]

there is no prime number between 1 and 2

badbadger

Joined: 18 Apr 06
Moves: 2443

28 May 06 01:02

Originally posted by Derfel Cadarn
Derfel Pime Number Fact

Any number that individually adds up to be a divisible of three can be divided by three.

Example: 2571

2+5+7+1=15

Not prime.

but 87 = 8 + 7 =15

87 is a prime number

Nordlys

The sky

Joined: 05 Apr 05
Moves: 10385

28 May 06 01:03

Originally posted by badbadger
there is no prime number between 1 and 2

1 is not a prime.

Nordlys

The sky

Joined: 05 Apr 05
Moves: 10385

28 May 06 01:05

Originally posted by badbadger
but 87 = 8 + 7 =15

87 is a prime number

87 = 3 x 29

~~trevor33~~

my island

Joined: 10 Nov 05
Moves: 17944

28 May 06 01:07

Originally posted by Nordlys
87 = 3 x 29

hay nordlys, i forgot to ask - how did you know the irish words for good night?