Discussion in 'Computer Support' started by Plato, Dec 13, 2004.

1. ### PlatoGuest

If I took a penny and flipped it 100 times and 99 times it came up Heads
what are the chances of it coming up Heads again on the 101st toss?

A: 50%
B: 75%
C: 99%

Plato, Dec 13, 2004

2. ### The Old SourdoughGuest

Plato gibbered the following deranged nonsense:
> If I took a penny and flipped it 100 times and 99 times it came up Heads
> what are the chances of it coming up Heads again on the 101st toss?
>
> A: 50%
> B: 75%
> C: 99%
>

A:50%

--
The Old Sourdough
BEER!! The staff of life!!
Linux Registered User 5A020

The Old Sourdough, Dec 13, 2004

3. ### =?ISO-8859-1?Q?R=F4g=EAr?=Guest

Plato wrote:
> If I took a penny and flipped it 100 times and 99 times it came up Heads
> what are the chances of it coming up Heads again on the 101st toss?
>
> A: 50%
> B: 75%
> C: 99%

Just now learning about statistics? It's always 50%, the penny can't
remember what it's done in the past.

=?ISO-8859-1?Q?R=F4g=EAr?=, Dec 13, 2004
4. ### Harvey GrattGuest

Rôgêr wrote:

> Plato wrote:
>
>> If I took a penny and flipped it 100 times and 99 times it came up Heads
>> what are the chances of it coming up Heads again on the 101st toss?
>>
>> A: 50%
>> B: 75%
>> C: 99%

>
>
> Just now learning about statistics? It's always 50%, the penny can't
> remember what it's done in the past.

Only if the penny and the experiment aren't rigged. The real question
should be "what is the probability that the experiment is rigged given
the data?"

Harvey

Harvey Gratt, Dec 13, 2004
5. ### YddapGuest

In news:jTlvd.753770\$8_6.33719@attbi_s04,
Harvey Gratt <> opined very noisily:
> Rôgêr wrote:
>
>> Plato wrote:
>>
>>> If I took a penny and flipped it 100 times and 99 times it came up
>>> Heads what are the chances of it coming up Heads again on the 101st
>>> toss? A: 50%
>>> B: 75%
>>> C: 99%

>>
>>
>> Just now learning about statistics? It's always 50%, the penny can't
>> remember what it's done in the past.

>
> Only if the penny and the experiment aren't rigged. The real question
> should be "what is the probability that the experiment is rigged given
> the data?"
>
> Harvey

99%

--

Yddap

Yddap, Dec 13, 2004
6. ### Jock StrapGuest

Plato wrote:

> If I took a penny and flipped it 100 times and 99 times it came up
> Heads what are the chances of it coming up Heads again on the 101st
> toss?
>
> A: 50%
> B: 75%
> C: 99%

A:50%. And no, it would never come up heads 99 times in a row either.
Yes, it's theoretically possible, but practically it wouldn't happen.

Jock Strap, Dec 13, 2004
7. ### Flying TigerGuest

"Plato" <|@|.|> schreef in bericht
news:41bdcf2b\$0\$62698\$...
> If I took a penny and flipped it 100 times and 99 times it came up Heads
> what are the chances of it coming up Heads again on the 101st toss?
>
> A: 50%
> B: 75%
> C: 99%
>

Normally 50% cz lack off memory off penny,

if it came 99 times head up, i would check the other side off penny,

F.

Flying Tiger, Dec 13, 2004
8. ### PlatoGuest

The Old Sourdough wrote:
>
> > If I took a penny and flipped it 100 times and 99 times it came up Heads
> > what are the chances of it coming up Heads again on the 101st toss?
> >
> > A: 50%
> > B: 75%
> > C: 99%

>
> A:50%

False.

Plato, Dec 13, 2004
9. ### PlatoGuest

Harvey Gratt wrote:
>
> > Just now learning about statistics? It's always 50%, the penny can't
> > remember what it's done in the past.

>
> Only if the penny and the experiment aren't rigged. The real question
> should be "what is the probability that the experiment is rigged given
> the data?"

Correct. For a penny to come up Heads 99% of the time it has to be
rigged.

I imagine that you Harvey dont work in a cube but have an office with a
window

Plato, Dec 13, 2004
10. ### PlatoGuest

Jock Strap wrote:
>
> > If I took a penny and flipped it 100 times and 99 times it came up
> > Heads what are the chances of it coming up Heads again on the 101st
> > toss?
> >
> > A: 50%
> > B: 75%
> > C: 99%

>
> A:50%. And no, it would never come up heads 99 times in a row either.

False.

Plato, Dec 13, 2004
11. ### PlatoGuest

Rôgêr wrote:
>
> Plato wrote:
> > If I took a penny and flipped it 100 times and 99 times it came up Heads
> > what are the chances of it coming up Heads again on the 101st toss?
> >
> > A: 50%
> > B: 75%
> > C: 99%

>
> Just now learning about statistics? It's always 50%, the penny can't
> remember what it's done in the past.

False.

Plato, Dec 13, 2004
12. ### PlatoGuest

Flying Tiger wrote:
>
> > If I took a penny and flipped it 100 times and 99 times it came up Heads
> > what are the chances of it coming up Heads again on the 101st toss?
> >
> > A: 50%
> > B: 75%
> > C: 99%

>
> Normally 50% cz lack off memory off penny,
>
> if it came 99 times head up, i would check the other side off penny,
> maybe head on both sides....

It came up once in Tails tho You can do the same with modified dice.

Plato, Dec 13, 2004
13. ### Jock StrapGuest

Plato wrote:

>>> If I took a penny and flipped it 100 times and 99 times it came up
>>> Heads what are the chances of it coming up Heads again on the 101st
>>> toss?
>>>
>>> A: 50%
>>> B: 75%
>>> C: 99%

>>
>> A:50%. And no, it would never come up heads 99 times in a row
>> either.

>
> False.

Which bit? The 50% or the 99 times? And both are true, anyway.

Jock Strap, Dec 13, 2004
14. ### PlatoGuest

Jock Strap wrote:
>
> >>> If I took a penny and flipped it 100 times and 99 times it came up
> >>> Heads what are the chances of it coming up Heads again on the 101st
> >>> toss?
> >>>
> >>> A: 50%
> >>> B: 75%
> >>> C: 99%
> >>
> >> A:50%. And no, it would never come up heads 99 times in a row
> >> either.

> >
> > False.

>
> Which bit? The 50% or the 99 times? And both are true, anyway.

Plato, Dec 13, 2004
15. ### ex cathedraGuest

"Plato" <|@|.|> wrote in message
news:41bdcf2b\$0\$62698\$...
> If I took a penny and flipped it 100 times and 99 times it came up Heads
> what are the chances of it coming up Heads again on the 101st toss?
>
> A: 50%
> B: 75%
> C: 99%
>

If the coin is unbiased, it's 50-50, just like always.

However, the smart money here says the flipping is rigged since the chances
of 99 heads in a row in an unbiased coin is one out of two to the 99th
power...(you do the math)!

X

ex cathedra, Dec 13, 2004
16. ### Jim ScottGuest

ex cathedra wrote:

> "Plato" <|@|.|> wrote in message
> news:41bdcf2b\$0\$62698\$...
> > If I took a penny and flipped it 100 times and 99 times it came up
> > Heads what are the chances of it coming up Heads again on the 101st
> > toss?
> >
> > A: 50%
> > B: 75%
> > C: 99%
> >

>
> If the coin is unbiased, it's 50-50, just like always.
>
> However, the smart money here says the flipping is rigged since the
> chances of 99 heads in a row in an unbiased coin is one out of two to
> the 99th power...(you do the math)!
>
> X

Agreed. Coins have no memory.
--
Jim

Tyneside - North East of England
To email me directly omit the X from my address

Jim Scott, Dec 13, 2004
17. ### RichardGuest

Plato wrote:

> If I took a penny and flipped it 100 times and 99 times it came up Heads
> what are the chances of it coming up Heads again on the 101st toss?

> A: 50%
> B: 75%
> C: 99%

Since you've ruled out 50% as your correct answer, which it should be, that
leaves two choices.
So the answer to YOUR question is 75% because 99% is impossible given the
conditions.

Technically though, the answer is correctly 50% because there are only 2
sides to the coin.

Besides, the vast majority of coins will undoubtedly land on the "tail" side
more times than not, due to the variance in the weight of each "side".

ya think he bought that one eh?

Richard, Dec 13, 2004
18. ### Trent SCGuest

> > If I took a penny and flipped it 100 times and 99 times it came up Heads
> > what are the chances of it coming up Heads again on the 101st toss?
> >
> > A: 50%
> > B: 75%
> > C: 99%

>
> If the coin is unbiased, it's 50-50, just like always.
>
> However, the smart money here says the flipping is rigged since the

chances
> of 99 heads in a row in an unbiased coin is one out of two to the 99th
> power...(you do the math)!

Yes, and don't confuse "mathematical probability" and "likely outcome". The
mathematical probability is 50%, as each event (a coin toss) is a unique
event in its own right, without influence from other events. As other
posters have said, the coin has no memory. It is statistically possible to
have a coin land on tails 99 times in a row. Lunatic and more unlikely than
my scoring tonight with Kylie, but still statistically possible.

However, if you look at the likely outcome, you are introducing
non-mathematical elements into the calculation. I personally wouldn't put
half the kid's college fees on tails, and I doubt if you would either, but
there you go.

Trent SC, Dec 13, 2004
19. ### anthonyberetGuest

"Plato" <|@|.|> wrote in message
news:41bdcf2b\$0\$62698\$...
> If I took a penny and flipped it 100 times and 99 times it came up Heads
> what are the chances of it coming up Heads again on the 101st toss?
>
> A: 50%
> B: 75%
> C: 99%

None of them - it could land on its edge.
It would be very close to but lower than 50% assuming it was an
equally-balanced coin.
After 99 heads I would be tempted to check it wasn't a double header or a
trick coin in some way.
After all, what are the chances of throwing 99 heads in a row with an
even-chance coin?
(very, very low).
--
To those that can, do the rest of us a favour - vote Kerry.
(Don't endorse deceit).

anthonyberet, Dec 13, 2004
20. ### anthonyberetGuest

"Jock Strap" <> wrote in message
news:...
> Plato wrote:
>
> > If I took a penny and flipped it 100 times and 99 times it came up
> > Heads what are the chances of it coming up Heads again on the 101st
> > toss?
> >
> > A: 50%
> > B: 75%
> > C: 99%

>
> A:50%. And no, it would never come up heads 99 times in a row either.
> Yes, it's theoretically possible, but practically it wouldn't happen.
>

It just depends how many times you throw it - a 99 run of heads is 100%
certain with an infinite number of throws.

anthonyberet, Dec 13, 2004