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

You are not logged in.

- Topics: Active | Unanswered

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

**New Problem:**

**A list of 1000 zeroes is created called M. A random number is picked from 1 to 1000. Each time one of these is picked, the zero in the list ( at that index ) is changed to a 1. For instance if the random number is 276 then M[276]=1. What is the average number of random numbers that must be picked to have 200 ones in the list?**

**A says) 200 of course.**

**B says) Not likely A the exact answer is C says) I got 251.18725416273654 and that is darn close.**

**D says) That is what I got!**

**E says) Nope, I like B's answer.**

**What is B's answer?**

**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.**

**Online**

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,979

Hi Bobby,

*Last edited by phrontister (2012-07-23 21:32:54)*

"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: 92,926

Hi phrontister;

**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.**

**Online**

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,979

Hi Bobby,

"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: 92,926

Hi phrontister;

**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.**

**Online**

**gAr****Member**- Registered: 2011-01-09
- Posts: 3,479

Hi bobbym,

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

Hi gAr;

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

**Online**

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,979

Hi Bobby,

I found my error with the shortcut and fixed it. Both methods give the same answer.

*Last edited by phrontister (2012-07-24 14:28:41)*

"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

**gAr****Member**- Registered: 2011-01-09
- Posts: 3,479

Hi bobbym,

I think you are right.

I did not try simulation.

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

Hi gAr;

Okay, give it a try when you have some time. Thanks for working on the problem.

Hi phrontister;

That is good. Did you know a solution in M earns extra credit? Thanks for looking at the problem.

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

**Online**

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,979

Hi Bobby,

Did you know a solution in M earns extra credit?

Xlnt! I'll send you my bank account details if I find an M solution.

Should I try one of my methods? If so, which one? Or did you mean your method (but I don't understand yours or gAr's because of my Year 4 high-school maths level).

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

Hi phrontister;

I meant for a simulation using M.

Should I try one of my methods?

Yes! Either one that you think will be easier to code in M.

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

**Online**

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,979

Ok, Bobby, I'll give that a go. Get ready for my cry for help, though, because at this early stage the task seems to be a bit daunting.

I've got no idea whatsoever about how go about it, other than to dive into M's help files with the hope that I can find some examples that relate to what I want to do...which may take a while.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

Hi phrontister;

You will do fine. Holler if you need help.

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

**Online**

**gAr****Member**- Registered: 2011-01-09
- Posts: 3,479

Hi bobbym,

"Believe nothing, no matter where you read it, or who said it, no matter if I have said it, unless it agrees with your own reason and your own common sense" - Buddha?

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

Hi gAr;

If you want to you can. Let me know when and I will make a thread there for yours and phrontister's.

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

**Online**

**gAr****Member**- Registered: 2011-01-09
- Posts: 3,479

Hi bobbym,

Yes, and maybe you too can post your code there so that users can have a choice among the tools of the trade!

"Data! Data! Data!" he cried impatiently. "I can't make bricks without clay."

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

Hi;

Will do!

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

**Online**

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

**New problem:**

**What is the diameter of the smallest circle that encloses x^2 + y^2 = 4 and (x - 2)^2 + (y - 4)^2 = 9?**

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

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,889

Hi bobbym

*Last edited by anonimnystefy (2012-09-06 01:15:42)*

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

Hi anonimnystefy;

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

**Online**

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,889

Hi bobbym

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

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

**Online**

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

**New problem;**

**What is the area of the smallest equilateral triangle that encloses x^2 + y^2 = 4 and (x - 2)^2 + (y - 4)^2 = 9?**

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

**Online**

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,926

**New Problem:**

**E says)**

**The sum**

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

**Online**