How smart is Cred Forums?

How smart is Cred Forums?

50% bait

1 in 4. has to be, right?

33%

2/3 now get back to class

>1 in 4. has to be, right?

That would be correct without the condition that at least 1 coin landed heads.

Flip 2 coins. 4 equally likely outcomes:

HH = 1/4
HT = 1/4
TH = 1/4
TT = 1/4

At least 1 landed heads, so only TT no longer a possibility, leaves:

HH = 1/3
HT = 1/3
TH = 1/3

1/3

25%, approximately. Studies have shown a very slight bias in a perfect toss performed by machines to land on heads.
For those who are too retarded to do the math: 2 coins + 2 possible results per coin = 1/2^2=1/4

doesn't change the probability though. I'm not buying it. its 1/4. fuck you.

Shit, just noticed the second part. It's about a 1/2 chance, since you only have to determine for one coin now.

probabilities:H/H
H/T
T/H

so 1/3 or 33% of chance

Wrong, the coin that is going to land on heads is not determined until both coins have been tossed. Either of them can land on heads so it's 1/3.

read about the Monty Hall problem. Eliminating options does affect the odds in end result.

Is Cred Forums really this retarded?

The answer is 1/3.

This is a conditional probability question, so use Bayes' theorem to solve.
P(A|B) = P(A∩B)/(P(B))

Explanation for faggots:

COnditional probability questions take the form:
>What is the probability of Event A given Event B?

OPs question is
>What is the probability that BOTH coins landed heads, given that AT LEAST ONE coin landed heads?

So here

A = "both coins are heads" = {(HH)} = 1/4
B = "at least one coin is heads" = {(HH), (HT), (TH)} = 3/4

P(A|B) = P(A∩B)/(P(B)) = (1/4)/(3/4) = 1/3

Pic Related

Its 50%. If one is already heads that means there is only 1 HT/TH possibility.
Therefore the only possible outcomes can be HH or HT, 1/2.

Basic statistics faggot

You guys must be niggers. This really isn't difficult.

You toss 2 coins and at least 1 landed heads, so you could have

>coin1=heads, coin2=tails
or
>coin1=tails, coin2=heads
or
>both coins=heads

Those are the only 3 options. All 3 are equally probable.

1/3

yeah i change my mind its 1/2 that makes most sense

>If one is already heads
No, at least 1 is heads. it could be either coin, meaning either coin could be tails, just not both at the same time.

HH, HT and TH are all valid results and all equally likely. If you don't believe me, do the xperiment yourself. toss 2 coins 100 times. Ignore all TT outcomes. Count how many times you got both heads.

100 tosses should look something like this:

HH = ~25 times
HT/TH = ~50 times

25+50 = 75

25 / 75 = 1/3

Samefag or retarded nigger?

you two are idiots
see

ye i'll just go do that. oh no wait I'm just going to call you a faggot instead.

Loving thoses threads

>can't do basic math
>refuses to test correct answer
>calls people who get it correct "faggots"

I'll take a large fries with that, thanks.

1/3

People who say 50% are either retarded or trolling.

it is twice as likely to land on either H/T or T/H than H/H
so they need to be distinguished, making the answer 1/3

its 1/5 because you get an extra chance because one is already heads