Can Sup Forums solve this?

Can Sup Forums solve this?

Other urls found in this thread:

en.wikipedia.org/wiki/Gambler's_fallacy#Coin_toss
youtube.com/watch?v=eBPqksG9nbA
twitter.com/AnonBabble

50\50

50%

Since one is already heads, for the other one to also be heads would be 50%. So it would be a 50% chance that in that flip they would both be heads

1/2 x 1/2 = 1/4

66%

Conditional probability states that it is 100% E(X | Y)

1/3

it can be:

HEAD-TAIL
TAIL-HEAD
HEAD_HEAD

TAIL-TAIL doesn't count because we already know that at least one coin lands on head

No, there are 3 possible equally likely outcomes of which only 1 is heads heads so it's ⅓.

About threefiddy

ITT: Ameritard education

Sh - Gh
Sh - Gt
St - Gh
St - Gt

St - Gt doesn't play. 1 out of 3. So 1/3.

33.3333 repeating %

Literally the only person in this thread that's right

this is correct

That would be the probability if we were just flipping random coins. However the question states at least 1 coin will be heads so the TT possibility is eliminated.

all that gets eliminated is the possibillty of tails tails, so it could be heads heads, tails heads, or heads tails, 33%

Literally the wrongest person in this thread

1 in 3 you stupid flat earth believing bitches

Guys are you all fucking retarded? It's just one coin. 50%. The one you know is heads doesn't matter.

Yeah I didn't read it properly. Just saw two heads up.

50% and anyone saying otherwise is a retard that either didn't take a statistics and probability class ever or they slept through it

en.wikipedia.org/wiki/Gambler's_fallacy#Coin_toss

if only this would ever be relevant outside of your high school math class.
but don't worry, people are impressed when you solve arbitrary math problems from elementary school

No its 50% because there is 2 options it either happened or it didnt

>didn't take a statistics class because this is literally the first eample of the first lesson in every stat class ever
answer is 33.33%

((1/3 * 1/2) / 3) * 2 = 0.1

>disregards the wikipedia entirely
answer is $183.941%

The gambler's fallacy is completely irrelevant to this problem. You failed your statistics class for sure.

one coin is always head, so other coin has heads or tails, so x to y is 50% (x is heads compare to y is tails)

>Why the probability is 1/2 for a fair coin
>We can see from the above that, if one flips a fair coin 21 times, then the probability of 21 heads is 1 in 2,097,152. However, the probability of flipping a head after having already flipped 20 heads in a row is simply 1/2. This is an application of Bayes' theorem.
gee you sure know your shit user

...

>1+2=2+1
>not the same thing

This. The outcome of one coin doesn't change the probability for the other.

You're dumb as rocks. There is additional information given in the original problem that helps you exclude some cases. The probability of getting both heads is 1/3.

Someone wrote the wrong answer on a chalk board. Amazing.

Which part is wrong?

They are different coins and the op doesn't specify which one is the one thats guaranteed to land on heads.

Possibility 1 = both are heads.
Possibility 2 = silver is heads.
Possibility 3 = gold is heads.

3 possible outcomes means its 33%

The additional information is that one coin is already heads, so you only need to calculate the possible outcomes of the second coin, because the first one is an invariant.
Which is exactly what the gambler's fallacy talks about.
Ask your high school teacher tomorrow, he may be able to explain it to you with apples and oranges.

This shit A G A I N ?

Any fucker in this thread able to read? This isn't a statistics question, this is a straight up trust issue.

> you are INFORMED that at least one of the coins landed heads up

Who's doing the informing and how do we know that bitch isn't lying and they're both tails?

>The additional information is that one coin is already heads
Yes, one or the other, or both are already heads.

>so you only need to calculate the possible outcomes of the second coin
What, no. This conclusion is unfounded. The information only tells you that both coins being tails didn't happen. Every other possible case could still have happened.

god dommot, answer the question assuming the person didn't lie to you.

It doesn't matter which coin landed heads, because you want to know what's the probability that both landed heads.
Gold-Silver = Silver-Gold, so that's the same case.
Knowing that one of the coins landed heads, and knowing that one outcome doesn't affect the other (gambler's fallacy) it's clear that the probability is 50%.
If you want the math it's in the wikipedia article I showed, it even links to Bayes Theorem

No. After you flip both coins and without looking at the result all four outcomes are equally likely and distinct.

Yes, if you don't know one of the outcomes the answer is 1/2 * 1/2 (Bayes Theorem).
No, this isn't the case because you already know part of the outcome.
Go read the wikipedia article and stop arguing like a retard.
An analogy of this problem is presented with 21 coins. I'm sure you can extrapolate.

The gambler's fallacy applies in a situation like the following: I flip a coin and it lands up heads. I flip another coin, what is the probability that it lands up heads? It's 1/2, the first event has no influence on the latter event.

It doesn't apply in this case though. You flip two distinct coins, this is a single event. both the gold and the silver coin have two possible outcomes each with equal probability. That makes 4 possible outcomes in total. Of those four, you are told one is to be eliminated.

50%

People lie. And if I had the opportunity to fuck with some smartass maths guy by lying about a coin toss, I'd lie my ass off.

Just cos.

>single event
This is were you are wrong.
One coin's outcome isn't affected by the other.
You have two coins, one you already know is a head, so you only care about the other.
That leaves the probability of a single coin landing head, which is 50%.

tail-head and head-tail are the same possibility. If one coin is already head the probability depends on the other coin that is 50%

And which one is that?

Where in the question does it say that matters?

>one you already know is a head
But you don't know WHICH one is heads.

oh okay, so the probability that gold lands heads and silver lands heads is different than the probability that silver lands heads and gold lands heads

ITT: People without brains. Since we know one coin lands on heads, the probability of the other coin landing on heads is 50%. It's not a 1/3 chance since there is only two possible outcomes.

Either the second coin lands on heads or it doesn't. One is already guaranteed to be heads.

No, but their combined probability is twice the probability of both being heads.

In the part that says "You are informed that at least one of the coins landed heads up". At least one. Not "The gold one landed heads up" or "The silver one landed heads up".

One coin is known heads. We know it. So coin 1 is heads. Coin two can only be heads or tails.

What the fucking retard did on the board didn't reflect the info we were given. We were told one coin is heads. We were not told "they aren't both tails." If we were he would be right to only cross that off. However we can cross two off because the H-T and T-H are the same because the H is always the same coin in those two so they only represent one possibility.

A = both landed heads up
B = at least one landed heads up

P(A|B) = P(A and B) / P(B)

P(A and B) = 0.25
P(B) = 0.75
P(A|B) = 0.25 / 0.75 = 0.33

33%

this.

"At least one is heads" is equivalent with "they aren't both tails".

Both coin flips are independent of each other, One having landed heads up has zero bearing on the second coin. The likely hood of any coin landing heads up is 50/50 (If you discount the possibility of a coin landing on its side)

If your maths include the first coin in any way, that's not how chance works. This isn't 'The Monty Hall problem' where outcomes can effect each other.

I could flip a hundred coins, and the outcome per coin is in no way effected by previous flips. Any pattern you see is irreverent to the outcome of the next flip.

The possible outcomes are
Head- Head
Head- Tail
50 / 50
(Head-Tail and Tail-Head is the same result as the coins are flipped simultaneously)

Anyone who discounts this needs to look into 'gambler's fallacy' and 'The Monty Hall problem'

...

It doesn't say it matters which coin is heads up, only that you are informed one is heads up. It doesn't matter which coin that is. May as well be tossing one coin

how do people not understand that head tails and tails head, whilst giving the same result, are not equal to the chance of head head

It doesn't matter whether it's the gold or silver one. All that matters is that there is one. It's 50/50

Unless the fucker doing the 'informing' is lying to us. That's a variable that must be considered.

Literally wrong.

It doesn't matter which coin lands heads and which doesn't. One is guaranteed to hit heads. The probability that BOTH land on heads is teetering on the ONE coin landing heads as well, which is a 50% possibility.

the question misleads you, if it was phrased like, what is the probability of 2 coins both landing heads taking into account combinations of flipping 2 coins, giving 25% of two heads

however it says one coin is X, what is the probability the other is also X, 50% as the options for that coin are X, or Y

coin A is X
coin B is either X or Y(aka the only variable)

after the flip, so tails tails is thrown out

silver = heads - gold tails
or
silver = tails -gold heads
or
silver = heads- gold heads

3 equal possibilities

except that is not the question posed by OP

wew i feel dumb i didnt get it before

no, one coin is heads
what is the chance the other coin is heads
50 FKING PERCENT

hes wrong though
possible outcomes as defined by the OP
ONE coin heads(stated as true) ONE coin tails
ONE coin heads(stated as true) ONE coin heads
the question simply asks what the probability of ONE coin being a specific outcome

The question isn't
>Which coin is heads up
HT and TH is the same result

HH or (HT / TH) = 50/50

> Umad.jpg
Both coins are double-sided. Probability - 100%

...

it says what is the probability that both the heads landed face up
if you flipped the coins 40 times and assuming they landed perfectly fair 10 would be ignored due to having the tails-tails result
20 of them would have tails - heads
10 of them would have heads - heads
if you have the information that one of them them is a head 20 of those times the other coin is tails
10 of those times the other coin is a head
20/10 is 50%

it _literally_ asks "What is the probability that both are heads?". Both is not one.

Still wrong question, see:

>20/10 is 50%
What are you retarded or something? You were right until the end. if something happens 20 times compared to 10 times assuming a 100% chance of something happening then the thing happening 20 times happens at a 66% probability
im sure everyone is baiting at this point

No. If you flip two fair coins the probability that both are heads is 1/4, the probability that both are tails is 1/4 too and the probability that one is heads and one is tails is the remaining 50%. This is _exactly_ represented in the die interpretation.

one coins outcome is known, you are only figuring the probability of one coin having the same outcome as the other
if no outcome was known, it would be 25%, but you know one outcome, also question deals in combinations, not permutations, so H/T is the same as T/H

66.6666666666666666666666666%

1/3

You don't know one outcome. You only know that of both coins, at least one is heads. This does not give you full information about one coin. If you had full information about one coin, you would be able to tell whether or not it was the gold or the silver coin that is guaranteed to be heads.

My supreme photoshop skills can end this argument. Now its 1/3.

Now fuck off and go do something productive so this thread dies and makes room for yet another trap thread filled with men with obvious man-asses wearing lingerie trying to convince themselves they are 'feminine'.

One head is guaranteed
Head+ head
Head+ Tails
50/50
How are you not getting this.jpg

What, no. Now it's 2/3.

...Possibility 4 = neither are heads?
so no. 25%

Shut. The. Fuck. Up. He said they were fair coins dumbass

head + head
head + tails
tails + head

youtube.com/watch?v=eBPqksG9nbA

tails + tails?

why is no one considering that both can be tails lmao. 4 possible outcomes, 25% chance

This is what you're trying to answer:
Which is not (op)s question

I was just pretending to be retarded; the thread

tails tails is thrown out if you did the experiment say 100 times 25 times wouldn't count because they would get tails tails

it depends

see

>thinking that if something is 25% chance it means indefinitely that it happens 25 out of 100 times

Knowing that at least one coin is heads does not fully determine the outcome of one of the coins. That statement alone doesn't tell you if it was gold or silver that is guaranteed to be heads.