Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,853

Hi Bobby,

*Last edited by phrontister (2010-04-10 12:37:58)*

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**ZHero****Real Member**- Registered: 2008-06-08
- Posts: 1,889

bobbym wrote:

Hi ZHero;

Sorry, can't even copy my own problem correctly. I have fixed the...

hi Bobbym!

You need to Double Check, Triple Check or say "n times" Check ur posts.

Don't be Sorry... Just Admit ur Mistake and be a lil'bit More Careful from next time!

*Last edited by ZHero (2010-04-09 04:53:26)*

If two or more thoughts intersect with each other, then there has to be a point.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi;

For the problem in post # 75

You are both right, A,B,C are all wrong the answer is 8.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi;

If r1, r2 and r3 are the roots of

and a ≠ 0 and

find a.

A says) No solutions.

B says) There are many answers for a but only one integer answer.

C says) There is only one answer for a.

D says) There are many answers but none of them are integers.

Who is right?

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi;

How many solutions are there to xyz = 360 when x ≠ y ≠ z and x,y,z > 0 ?

A) says 180

B) says 360

C) says 126

D) says 168

Who is right, hide your answers and back them up.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,853

Hi Bobby,

*Last edited by phrontister (2010-04-22 03:17:50)*

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

That's correct! Very good!

**In mathematics, you don't understand things. You just get used to them.**

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi;

What is the smallest integer that when cubed has it's last 4 digits the same?

A says ) 9999

B says ) There are some that are smaller than that.

C says ) There is only 2 smaller numbers.

Who is right and why?

**In mathematics, you don't understand things. You just get used to them.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,853

Hi Bobby,

*Last edited by phrontister (2010-04-23 12:43:35)*

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi phrontister;

That is correct! What does your LB code look like?

**In mathematics, you don't understand things. You just get used to them.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,853

Hi Bobby,

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi;

**In mathematics, you don't understand things. You just get used to them.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,853

Hi Bobby,

That's a neat trick!

Same answers as mine, and it took 18% less time.

*Last edited by phrontister (2010-04-24 00:10:10)*

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi phrontister;

Usually string operations, like converting integers to strings are very slow in almost every language. When possible work with integers, they are faster.

A tough one so be careful:

What is the smallest n, that n^3 has 4444 at the end?

A says ) No cube has 4444 on the end.

B says ) Of course there is some cube with 4444 on the end.

C says ) There are an infinite number of them but they are all 30 digits or more.

**In mathematics, you don't understand things. You just get used to them.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,853

Hi Bobby,

*Last edited by phrontister (2010-04-24 03:58:21)*

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi phrontister;

That is correct, can you give an old man a little help with your explanation? I am not following it.

**In mathematics, you don't understand things. You just get used to them.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,853

Hi Bobby,

*Last edited by phrontister (2010-04-25 11:22:03)*

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi phrontister;

**In mathematics, you don't understand things. You just get used to them.**

Offline

**ZHero****Real Member**- Registered: 2008-06-08
- Posts: 1,889

*Last edited by ZHero (2010-04-24 19:06:33)*

If two or more thoughts intersect with each other, then there has to be a point.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi ZHero;

Your solution is a real killer. It is devastating. I didn't think of that. Looks like a large happy face eating the earth.

**In mathematics, you don't understand things. You just get used to them.**

Offline

**ZHero****Real Member**- Registered: 2008-06-08
- Posts: 1,889

yeah.. that was the result when i tried to run a simple program in

Language on my

If two or more thoughts intersect with each other, then there has to be a point.

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,853

Hi Bobby,

I had already done something similar to yours:

*Last edited by phrontister (2010-04-25 11:29:16)*

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

There is a shorter proof of this that doesn't use a computer. Unfortunately I can't remember what it is or how I derived it. I will post it when I do. Good work, by the way.

**In mathematics, you don't understand things. You just get used to them.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,853

Hi Bobby,

*Last edited by phrontister (2010-04-25 15:17:17)*

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,882

Hi phrontister;

Do you have some idea in mind?

**In mathematics, you don't understand things. You just get used to them.**

Offline