The worlds first riddle!

ABORIGINAL

OR even ORIGINAL

[size=7]plain paper[/size]

Lzzie:

AORIGL = ORIGINAL


Mark:

PAPPLEAR = plain paper



You choose one of two identical looking bags at random. One bag has three black marbles and one white marble. The other has three white marbles and one black marble.

After choosing a bag you draw one marble out at random. You notice it is black. You then put it back and draw another marble out of the same bag at random.

What is the probability that the second marble drawn is black

MARBLES
[size=7]How about (3/4)^2 + (1/4)^2 = 9/16 + 1/16 = 10/16 = 5/8?[/size]

Where's Try?

Guten tag sehr geehrte Damen und Herren; I received some half baked message about Try being indisposed (read; in jail) and would I stand in and help out until he made bail.

Now, much as I would enjoy your company; I know diddly squat about math, so I told the management…I would give it a go!



Mark:


MARBLES
How about (3/4)^2 + (1/4)^2 = 9/16 + 1/16 = 10/16 = 5/8


Yeah hombre; close enough!



The probability of event A happening given that event B already happened is the probability of A and B happening divided by the probability that B happened. This can be pressed as Pr(A|B)=Pr(A and B)/Pr(B).

In this case A is drawing a black marble and B is having already drawn a black marble.

Pr(A and B) = (1/2) * [(3/4)^2 + (1/4)^2] = 5/16.
Pr(B) = 1/2.
Pr(A|B) = Pr(A and B)/Pr(B) = (5/16)/(1/2) = 10/16 = 5/8 ~ 62.5%.



Little Mismi40 who I believe I saw on the beach the other day; now, you would have thought that my eye would have been drawn to her gorgeous skin tone. However, and I don't want to play devils advocate here, it was the fact that she had her left fist clenched! Don't ask me why; unless it was to punch out her sister in law who was juxtapositional. :wink:



Solipsister, a name that fits you're My Space perfectly; wrote, "We don't know where he are."

Well, sister, I cudnt unnerstand a wurd use sed ... must be from some farn country. Coz the Lord willing and the creeks don't rise, I sure do hope to see that Eiffel Tire in Paris, Texas sometime!

Little Mismi40 who I believe I saw on the beach the other day; now, you would have thought that my eye would have been drawn to her gorgeous skin tone. However, and I don't want to play devils advocate here, it was the fact that she had her left fist clenched! Don't ask me why; unless it was to punch out her sister in law who was juxtapositional.

apparently you studied that picture - who knows why I had my fist clenched....could have been the old man in the speedo asking if he could borrow my sunscreen. He was standing in my sun. Could have been the fact that I had to go to the bathroom and the house was up the street and not an easy walk when you are full of Corona Lights...who knows? You really like that word don't you?

Hi Try,,, i miss you :wink: check out this awesome print ~

http://imagecache2.allposters.com/images/pic/SSPOD/SuperStock_1047-254~Creation-Posters.jpg

Paleoanthropology - paleontology and physical anthropology, is the study of ancient humans as found in fossil hominid ...

Thanks - I am old and wrinkly - but - not a fossil yet - you ass.

I wish you had told me this before I signed up for the course; I was told you sit around all day playing monopoly and gain credits for an ology. Nice bone structure though!

Assume that a pregnant woman's probability of giving birth to a girl is p, where p is determined at the mother's birth according to a uniform distribution from 0.4 to 0.6

If the woman's first child is a girl what is the probability her next child will also be a girl?

A uniform distribution modestly skirts the issue and the mother of all questions when conditional probability meets integral calculus.

Total probability is uniformly 5 times the range of p's = 0.2

The probability of two girls given one girl already is the probability of two girls divided by the probability of one girl first summed for p between 0.4
and 0.6

the integral of p*p / integral p

almost half time for a p

dodgy :wink:

Ok you may laugh, but I thought this was a one off gig. I had no idea it was to be a daily session till the guy returned…


Mismi carefully wrote, "dodgy"

Lemme just say that ever since college you have never forgiven me for saying,' I loved Elizabeth Montgomery aka Tabitha from Bewitched.

Ok; I made a mistake, will you forgive me now and leave my mule alone?





Sister:

A uniform distribution modestly skirts the issue and the mother of all questions when conditional probability meets integral calculus.

Total probability is uniformly 5 times the range of p's = 0.2

The probability of two girls given one girl already is the probability of two girls divided by the probability of one girl first summed for p between 0.4
and 0.6

the integral of p*p / integral p

almost half time for a p :wink:




The probability of event A happening given that event B already happened is the probability of A and B happening divided by the probability that B happened. This can be pressed as Pr(A|B)=Pr(A and B)/Pr(B).

In this case Pr(A and B) = 5*(The integral from 0.4 to 0.6 of p^2) =
5*(p^3/3 from 0.4 to 0.6) =
(5/3)*(.216 - .064) =
19/75 =~ 0.2533333
Pr(B) = 5 * The integral from 0.4 to 0.6 of p = 0.5 .
Thus the answer is 38/75 =~ .5066667


Sister; if Solipsism is an epistemological or metaphysical position that knowledge of anything outside the mind is unjustified, would an offer of a coffee be unacceptable?

You are forgiven and I have never messed with your mule...I called YOU a mule - though that is a nicer way to say it...And really it would be lovely to meet your wife - but you really should quit calling her such nasty things like mule. Very unbecoming. :wink:

Elizabeth Montgomery played Samantha, not Tabitha.

HA! :wink:

Thank you Stormwatch that is grounds for an ectoplasmic interlocutory!

Mismi, it's good to see you are obviously feeling better! If I said you had a cute body; would you hold it against me?