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

You are not logged in.

- Topics: Active | Unanswered

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

Okay.

"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: 102,922

Hi;

I am getting a mean of about 3.023

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

Offline

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

According to the simulation, a guess would be 3ab / pi .

But when I calculate the integral as done for the triangle, I get 6ab / pi .

"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: 102,922

Instead of running a simulation. Plot the 4 vertices a couple of dozen times. I think that will convince you that the answer is very close to 3.025

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

Offline

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

Yes, I need to rethink the analytical way then.

"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: 102,922

Yes, I need to rethink the analytical way then.

That is probably true. Looking at each quadrilateral created they were all simple and all had vertices on the ellipse. I have a geogebra demonstration too.

I have a chore to do so I will be offline for awhile. See you then.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

Offline

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

Okay, see you later.

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,922

Hi gAr;

Any results yet?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

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

Hi,

Nothing other than the results I've told earlier.

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,922

Hi;

I am having a little bit of trouble with it too.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

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

It's okay..

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,922

I am wondering why. Is it because there are many types of quadrilaterals?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

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

I'm not sure why.

Need to take a break, see you later.

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,922

Hi;

Okay, see you later. Thanks for coming in.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

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

B is about to fly of on a plane. He's got his ticket, but, because of wasting time in the snack bar, he was the last passenger in the line for boarding the plane. He gets in line and, thinking about how long he'll have to wait, he remembers that the tickets for his plane, which holds a hundred passengers, have been sold out. He also notices that the first person in line is a stubborn, old lady from his neighborhood whose eyesight is not the best. He knows that she will enter the plane and take a random seat and also that each passenger after will take his own seat if it is free and a random seat if his own is taken. B is wandering what his chances are of sitting in his own seat.

Same problem was asked in brilliant by a member there!

https://brilliant.org/community-problem/lost-boarding-pass/?group=AaGVLnK0JXOo

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,922

Hi gAr;

Probably got it while reading some book. It is a fairly standard problem.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

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

That's right, just saying.

Because I looked back here to enter the answer.

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,922

Hi;

Where did you find it?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

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

Hi,

Find what?

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,922

The quote in post #2465. Where did you find it?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

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

That was asked by anonimnystefy in this thread.

Searched it using keywords: seat site:mathisfunforum.com

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

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,922

Hi;

I got it thanks.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,922

**New problem:**

**Hi;**

**A student is taking 4 courses and there is to be a test in each course next week (Monday to Friday). What is the probability that there will be at least two tests on the same day?**

**A says) 106 / 125**

**B says) 65 / 70**

**C says)100!, I ran a simulation.**

**D says) C's answer looks right...**

**E says) I like B's answer but am not sure. He made a few assumptions.**

**What answer do you like?**

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**

Offline

**ShivamS****Member**- Registered: 2011-02-07
- Posts: 3,648

I like B's answer too, but I might be making a couple of assumptions.

*Last edited by ShivamS (2014-05-15 12:57:02)*

Offline

?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline