rufruf
Posts: 42
Joined: Wed Oct 25, 2006 4:55 pm

Just A Math Problem

Mon Nov 13, 2006 1:01 am

Three people get a motel room. Each is charged $10.00 ( 3 x 10 = $30.00 )

The desk clerk figures he has over charged them by $5.00 and tells them so.

They decide that the 3 people will be refunded a $1.00 each and the clerk will

keep the other $2.00 ( 3+2 = 5 ). So each person actually only paid $9.00

instead of the $10.00. Right ? 3 x $ 9.00 = $ 27.00 and the $2.00 the clerk

kept =$29.00.... Suddenly a Dollar go's missing.



Go Figure
 
Klaus
Posts: 20578
Joined: Wed Jul 11, 2001 7:41 am

RE: Just A Math Problem

Mon Nov 13, 2006 1:14 am

The proper sum would have been 30 - 5 = 27 - 2 = 25. Nothing is missing.
 
RichardPrice
Posts: 4474
Joined: Sat Apr 23, 2005 5:12 am

RE: Just A Math Problem

Mon Nov 13, 2006 1:15 am

The extra dollar never existed.

The original amount is $30.
The room is $25.
The 'pocketed amount' is $2.
The refunded amount is $3.

$9 x 3 = $27

The amount the Clerk pockets is within the $9 paid, the $3 given back makes the total up to $30, the $2 is deducted from the $27 not added to make the $25 room cost.
 
Go3Team
Posts: 3156
Joined: Sun Mar 14, 2004 1:19 am

RE: Just A Math Problem

Mon Nov 13, 2006 1:25 am

Must be the new math they are teaching in schools these days.
Yay Pudding!
 
rufruf
Posts: 42
Joined: Wed Oct 25, 2006 4:55 pm

RE: Just A Math Problem

Mon Nov 13, 2006 1:50 am

I still only paid $9.00 . as the other two people did . I started with $10.00 and I got a dollar back. I'm happy only pay in $9.00 .

Try it around a table and use tooth picks , or matches , or stir sticks.

count them as you pass them back and forth.

It's all in interpretation. Logic ? maybe. numbers don't lie ............ right
 
RichardPrice
Posts: 4474
Joined: Sat Apr 23, 2005 5:12 am

RE: Just A Math Problem

Mon Nov 13, 2006 2:06 am

Quoting Rufruf (Reply 4):

It's all in interpretation. Logic ? maybe. numbers don't lie ............ right

Actually, in the puzzle given in your original post, numbers do lie.

You say that the three people get $1 each back, and the motel clerk pockets $2.

Then you say that $10 - $1 = $9. Thats reasonable enough.

However, in that $9 is a cut of the $2 the Clerk keeps, so to add it on later ($27 + $2 = $29) is wrong because its already counted in the running total. What should be added on is the three $1 refunds, which takes the total up to $30 as expected.

Nothings missing, the puzzle as given is basically incorrect on purpose in order to provide the problem stated.

The real question is - what are three people doing with a motel room together? Why havent I been invited?

[Edited 2006-11-12 18:10:50]
 
sv2008
Posts: 591
Joined: Tue Aug 29, 2006 11:05 pm

RE: Just A Math Problem

Mon Nov 13, 2006 2:08 am

It's a trick with the wording.

Richard pretty much explaind it, but to add to it, the three really paid £0.66 each I think of the new amount to contribute to the extra them gave away.
 
tz757300
Posts: 2724
Joined: Mon Aug 08, 2005 6:21 am

RE: Just A Math Problem

Mon Nov 13, 2006 3:14 am

thats almost as bad as this

LETS GO MOUNTAINEERS!
 
sv2008
Posts: 591
Joined: Tue Aug 29, 2006 11:05 pm

RE: Just A Math Problem

Mon Nov 13, 2006 4:37 am

 
CastleIsland
Posts: 3212
Joined: Fri Mar 10, 2006 1:40 pm

RE: Just A Math Problem

Mon Nov 13, 2006 4:58 am

All I can say is that this sounds like an "hourly rate" at a sleazy motel in a bad part of town.  Wink
"People don't do what they believe in, they just do what's most convenient, then they repent." - Dylan
 
futuresdpdcop
Posts: 1226
Joined: Tue Feb 21, 2006 10:26 am

RE: Just A Math Problem

Mon Nov 13, 2006 10:42 am

Quoting CastleIsland (Reply 9):
All I can say is that this sounds like an "hourly rate" at a sleazy motel in a bad part of town.

Is this first hand knowledge or....?
 
Shinkai
Posts: 261
Joined: Sun Nov 05, 2006 4:39 pm

RE: Just A Math Problem

Mon Nov 13, 2006 11:21 am

BLEH! what an easy question!

how about you figure this one out:

f(x) = 3cos3x
f'(x) = ???
f''(x) = ???
f'''(x) = ???

now find the mclaurin series of f(x) up to x^3!!!
please relax, enjoy your flight... Good Luck!!
 
CastleIsland
Posts: 3212
Joined: Fri Mar 10, 2006 1:40 pm

RE: Just A Math Problem

Mon Nov 13, 2006 11:28 am

Quoting FutureSDPDcop (Reply 10):
Is this first hand knowledge or....?

That depends on what city we're talkin' 'bout. tongue 
"People don't do what they believe in, they just do what's most convenient, then they repent." - Dylan
 
dan2002
Posts: 2024
Joined: Tue Dec 17, 2002 7:11 am

RE: Just A Math Problem

Mon Nov 13, 2006 11:34 am

We spent a whole period in economics talking about this problem...
A guy asks 'What's Punk?'. I kick over a trash can and its punk. He knocks over a trash can and its trendy.
 
iamcanadian
Posts: 704
Joined: Wed May 30, 2001 6:53 am

RE: Just A Math Problem

Mon Nov 13, 2006 1:27 pm

Quoting Shinkai (Reply 11):
f(x) = 3cos3x
f'(x) = ???
f''(x) = ???
f'''(x) = ???

f'(x) = -9sin(3x)
f''(x) = -27cos(3x)
f'''(x) = 81sin(3x)

Quoting Shinkai (Reply 11):
now find the mclaurin series of f(x) up to x^3

What is a Mclaurin series?  confused 
Shut up and calculate.
 
RichPhitzwell
Posts: 1285
Joined: Mon Jul 24, 2006 5:19 am

RE: Just A Math Problem

Mon Nov 13, 2006 1:36 pm

Quoting Dan2002 (Reply 13):
We spent a whole period in economics talking about this problem...

Are you serious? A simple division vs multiplication problem?


Here is one for ya what is a 30% markup of $100

$130

or

$142.85

Warning, becomming drunker by the sip.

[Edited 2006-11-13 05:37:38]
Nonav.com kinda like Whiners except the lights are on and the pimps been paid
 
rufruf
Posts: 42
Joined: Wed Oct 25, 2006 4:55 pm

RE: Just A Math Problem

Thu Nov 16, 2006 4:46 pm

Hell I was just bringing up a point . Jessss Sorry I brought it up.

Never mind

But three investors invest 3 million dollars ...and the accountant takes 2 million.. and the ......
 
Kay
Posts: 1797
Joined: Fri Mar 01, 2002 3:41 pm

RE: Just A Math Problem

Thu Nov 16, 2006 11:16 pm

30% markup of $100 is 130 because the markup is of 100.

But if you say that "sales have fallen 30% this year, to 100", then it means that last year the sales were 142.85.

Easy.. as well the initial problem, which was a trap for really "unmathematical" people only  Smile

Kay
 
docpepz
Posts: 1706
Joined: Thu May 24, 2001 8:20 pm

RE: Just A Math Problem

Thu Nov 16, 2006 11:36 pm

f'(x) = -9sin(3x)
f''(x) = -27cos(3x)
f'''(x) = 81sin(3x)

http://mathworld.wolfram.com/MaclaurinSeries.html

That's what the Maclaurin Series is. So since we have

f(x) = 3cos(3x)
f'(x) = -9sin(3x)
f''(x) = -27cos(3x)
f'''(x) = 81sin(3x)

The Maclaurin series is till x^3 is as follows:

3 - 15.5x^2

The coefficient of x^3 is zero since sin 0 = 0 thus the answer stops there.

Pretty simple if you ask me, it's just substituting values into equations. Requires no brains!

Now Shinkai here is a question for you. You took SIA from Singapore to Perth in 2001. When you changed planes in Singapore to catch the flights to Perth, You thought you were in:

1)Asia
2)Europe
3)Mars
4)A Hotel Room with 3 Men
 
vikkyvik
Posts: 11755
Joined: Thu Jul 31, 2003 1:58 pm

RE: Just A Math Problem

Thu Nov 16, 2006 11:52 pm

Quoting DocPepz (Reply 18):
Now Shinkai here is a question for you. You took SIA from Singapore to Perth in 2001. When you changed planes in Singapore to catch the flights to Perth, You thought you were in:

1)Asia
2)Europe
3)Mars
4)A Hotel Room with 3 Men

 rotfl 

Priceless!

But remember, Stephen Hawking doesn't do geography (geology).
I'm watching Jeopardy. The category is worst Madonna songs. "This one from 1987 is terrible".
 
docpepz
Posts: 1706
Joined: Thu May 24, 2001 8:20 pm

RE: Just A Math Problem

Fri Nov 17, 2006 12:01 am

My bad, the answer should be 3 - 13.5x^2. Not 15.5 as I said above. I did my A Levels in 2000 which was the last time I touched Maclaurin's series. Thankfully I still remember calculus though I've clearly forgotten how to do simple division. 27/2 is indeed 13.5 and not 15.5.
 
linco22
Posts: 1278
Joined: Tue Jun 14, 2005 6:16 am

RE: Just A Math Problem

Fri Nov 17, 2006 12:01 am

Its simple. Skidmarks was the clerk and tried to rip them off.

Its pathetic.
 
JRadier
Posts: 3943
Joined: Mon Sep 27, 2004 11:36 pm

RE: Just A Math Problem

Fri Nov 17, 2006 12:13 am

Quoting Rufruf (Reply 4):
numbers don't lie ............ right

wich is why there are lies, damn lies and statistics
For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and ther
 
rufruf
Posts: 42
Joined: Wed Oct 25, 2006 4:55 pm

RE: Just A Math Problem

Sun Nov 19, 2006 4:13 pm

What a lot of fun !!!

Gotta love the fraction answers.

The answer is ?

Did you all have a good sleep in what ever motel you were in ?

I actually have a life .


New one ..

Which planet takes longer to circle the sun then it's day .
 
Shinkai
Posts: 261
Joined: Sun Nov 05, 2006 4:39 pm

RE: Just A Math Problem

Sun Nov 19, 2006 6:46 pm

Quoting DocPepz (Reply 18):
Now Shinkai here is a question for you. You took SIA from Singapore to Perth in 2001. When you changed planes in Singapore to catch the flights to Perth, You thought you were in:

1)Asia
2)Europe
3)Mars
4)A Hotel Room with 3 Men

i choose 1.

see you in Singapore Changi Airport this december!
please relax, enjoy your flight... Good Luck!!
 
RichardPrice
Posts: 4474
Joined: Sat Apr 23, 2005 5:12 am

RE: Just A Math Problem

Sun Nov 19, 2006 8:06 pm

Quoting Rufruf (Reply 23):
Which planet takes longer to circle the sun then it's day .

If you actually mean what you wrote literally then nearly all the planets have a year longer than their own day - only Venus has a day longer than its year.
 
rufruf
Posts: 42
Joined: Wed Oct 25, 2006 4:55 pm

RE: Just A Math Problem

Wed Nov 22, 2006 4:12 pm

Actually the answer is Mercury.

Mercury takes 88 days to revolve around the sun . It's rotation ( as it spins on it's axis takes something like 288 days ). Of course we are talking about earth days.
 
RichPhitzwell
Posts: 1285
Joined: Mon Jul 24, 2006 5:19 am

RE: Just A Math Problem

Wed Nov 22, 2006 4:22 pm

Quoting Kay (Reply 17):
30% markup of $100 is 130 because the markup is of 100.

But if you say that "sales have fallen 30% this year, to 100", then it means that last year the sales were 142.85.

Easy.. as well the initial problem, which was a trap for really "unmathematical" people only

Kay

It is very simple...but you can mark up both ways to come to two different profit levels and still claim to be a 30% markup. As a PM at one company we would multiply by 1.3 while at another company we would divide by .7 Its all fun and games until you retire... Funny how simple math fades as one grows beyond calculus though... Im really a retard at both, but im more likely to need a calculator for determining the 15% Tip for a $100 meal. Go figure.
Nonav.com kinda like Whiners except the lights are on and the pimps been paid
 
kalakaua
Posts: 1429
Joined: Tue Jan 27, 2004 5:23 pm

RE: Just A Math Problem

Wed Nov 22, 2006 8:55 pm

Okay... LAPLACE, anyone?! This is so fun!

Find L{f(t)} if

f"(t) + 3f'(t) - 8f'(t)=0, f(0)=1 and f'(0)=2

* L{f'(t)} =sL{f(t)} - f(0)


Theorem: L{y'(t)} = sL{y(t)} - y(0)

{y' -3y = 4e^5t
{y(0) = 6 <---initial condition
Gravity explains the motions of the planets, but it cannot explain who set the planets in motion.
 
rufruf
Posts: 42
Joined: Wed Oct 25, 2006 4:55 pm

RE: Just A Math Problem

Fri Nov 24, 2006 3:21 pm

To last post

When dos a equation have a ( if ) in it ? At least in chemeistry both sides are equal ( = )
 
SpinalTap
Posts: 388
Joined: Fri Mar 18, 2005 7:18 pm

RE: Just A Math Problem

Fri Nov 24, 2006 11:29 pm

Quoting Kalakaua (Reply 28):
Okay... LAPLACE, anyone?! This is so fun!

Find L{f(t)} if

f"(t) + 3f'(t) - 8f'(t)=0, f(0)=1 and f'(0)=2

* L{f'(t)} =sL{f(t)} - f(0)

An answer:
f(t) = exp(-1.5*t)*[cosh(sqrt(10.25)*t) + 3.5/sqrt(10.25)*sinh(sqrt(10.25)*t)]

Quoting Kalakaua (Reply 28):
Theorem: L{y'(t)} = sL{y(t)} - y(0)

{y' -3y = 4e^5t
{y(0) = 6 <---initial condition

y = 2*exp(5*t) + 4*exp(3*t)
"I get what they call a stipend, a stipend is like money but its such as small amount they don't really call it money"

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