Technology0 min ago
Coins Puzzle
38 Answers
If you flip a coin 19 times and it lands on tails all 19 times, what is the probability of it landing on tails the 20th time?
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It is SO little less than 50% that for all practical purposes it IS 50% or would some people actually prefer that we said 49.999999 recurring?
AND if it did end up on its side by some miraculous event (which I doubt anybody has ever seen happen) the coin would simply be flipped again to decide which way the 20th spin would go.
gen2 is as correct as far as anybody would want a correct answer so why introduce this pedanticism.
biley seems to prefer to ignore a possible outcome of a coin toss for the sake of keeping the numbers simple. I would hardly call it a miracle if a coin landed on its edge, just highly unlikely. (BTW I have witnessed coins landing in such a way as to roll on their edges before falling to one side so why is it such a leap of faith to assume that occasionally a coin may stay standing.)
Why is it pedantic to say that 50% is incorrect when you admit the existence of a third outcome by saying "if it did end up on its side"? I did not choose to put a definitive number (if one were to exist) on the 'correct' answer preferring instead to say "not quite 50%".
gen2 - To qualify your claim of 50% you should at least make mention of third outcome and then say you choose to ignore this possibility.
kempie, I am quite surprised at your reply. You have argued in the past that I would have difficulty in proving an answer and yet here you are, purely GUESSING that a coin MIGHT end up on its edge.
You say it might happen and that Gen2 should have said this. As you have never seen it happen it is MORE THAN a leap of faith to say it might - if you think it is possible, why have NONE of the coins that you have seen rolling onto their edges not actually stayed there?
You may spend a lifetime trying to get a coin to land up on its edge and I say you will fail every time. Unless you have proof that it can happen then you should not be asking someone to answer in a way that you THINK they should.
Yes, I HAVE somewhat changed my opinion that it might happen. This is a THEORY only and as you seem to be quite happy to say to gen2 that he should have said this or that, I think pedantry is quite apt for the way you answered joules99 question.
THECORBYLOON - You appear to agree with kempie yet you agree that this is a theory. As it is a theory do you not agree it is hardly worth mentioning until somebody can prove it can happen?
If there is anybody reading this who CAN prove it can happen, I will unreservedly apologise. ANYBODY?
THECORBYLOON - Why am I wasting time? One - I think that I have every right, just as you have or kempie has or anybody has, to query and even question a post.
You say it is possible - but if you have not seen it or know anybody who has, how can you be so dogmatic and say it can happen?
kempie - It was you who answered joules99 question so the onus is on you to prove it CAN happen. If you cannot, then why do you assume it can?
I note that you have not answered the question as to why you are asking gen2 to qualify his answer when you have no proof whatsoever.
Stick to the obvious answer joules99 and let those who believe in theoretical statistics go their own way.
biley From Middle Tennessee State University Dept of Physics and Astronomy website here
"When we toss a coin, there are basically only two pssible outcomes (neglecting the very small probability that the coin will land on its edge): either the coin will land heads up (H) or it will land tails up (T). For a single toss of a coin, there are thus only two possibilities: H or T."
Does that satisfy you?
No I am sorry THECORBYLOON but it doesn't.
This is still in the land of theoretical statistics. A theory is a theory is a theory. The Middle Tennessee State University may say it is a possibility but unless THEY have proof that it can happen, then all they are doing is covering themselves in case some person asks "well what about the chance of a coin landing on its edge?".
Thankyou for pointing out that site. I appreciate your doing so, but it sadly it does not provide the proof that a coin can land on its edge. I would love to see the proof that it can, I really would - it would be really interesting and, as I say, I would apologise completely.
But, if a person is going to make a statement that it can happen, then it is surely up to that person to provide evidence that would support it. If one does not have the proof, ie it is just a pet theory, then why post an answer that goes against a more typical answer provided by another poster? Does the original poster or the one posting the more prevalent answer gain in any way by this? I do not think so, which is why gen2's answer should not have been contradicted, in my opinion.
biley - sorry to burst your bubble but the onus is NOT on me to prove it CAN happen since you have already conceded the point in the very first line of your first post
'It is SO little less than 50% that for all practical purposes it IS 50%'. qoud erat demonstrandum.
But then you contradict this in the next paragraph and in a later post you say it will not happen if I spend a lifetime trying. How you can know this is beyond my comprehension because, unlike yourself, I am not prescient (other than I predict my Banned Answers total will increase because of this thread).
You would be better served not foretelling the future but sticking to your assertion that my initial answer was TOO correct for your liking.
kempie, I have already posted that I had changed my mind about my original answer, which you would see if you looked!
And again, I quoted my OPINION that you would fail every time - or had you not noticed that I used the words "I say" ?
Let me reiterate - it was you who contradicted gen2's original statement and so you are the one who has to provide the proof or admit that you could be wrong. I was wrong to agree with you in the first place that it could happen and for that I apologise to gen2 and to joules99.
You (like I) have read the POSSIBILITY that it may be true without trying to look for the proof that would make it true. As you have said in the past, just because we read something does not make it true, which is why I changed my mind and stated that until someone comes up with some proof, I will be of the opinion that it cannot happen.
I changed my mind also because I have looked at quite a few websites since my original post and there is not one I have seen that can provide the proof that would make my (and your) original assertions correct.
So quit telling me what or what not I would be better off doing just because you don't like what I say!
THECORBYLOON - I am sorry but I cannot see the relevance here. Whether I think that it is possible there is or has been life on another planet is just an opinion (I don't as a matter of fact) but the question of whether a coin can land on its edge can be proved if it does happen. I just want it to be proved!
As I said above, just because someone writes something somewhere about this or that, does not make it true. There are many websites that will tell you that Jesus was born of a virgin, performed many miracles and died and rose again. I believe that myself, but only because of faith - not because of proof - but somehow I doubt that just because it is writtten down that you believe it, do you?
So what is different about this topic? Nothing I think - you and kempie believe a coin may land on its edge - that is fine but perhaps you and kempie should come out and say that that is what you believe, rather than stating it as a fact when you have no proof. You yourself have admitted it is a theory - I agree, it IS a theory until backed with proof.
