Tom Winnifrith Bearcast 22 Feb: A dying cat, a moronic follower of Lenigas & Gavin Burnell's kiss of death

Comments

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   VINES

   22 February 2016, 07:59

   not bashing a ceo’s flip flop on horse hill bcos of his views on the eu is a non sequitur

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   Drunken Sailor

   22 February 2016, 08:13

   We are right, Monk is wrong – he should have spent less time on the river and then afterwards in the bar boring everyone with how they rowed up the river and then turned round and rowed back down the river.

   Sorry to hear about Tara, nothing lives for ever, at least you gave her a loving home in which to see out her days.

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   wildrides

   22 February 2016, 08:19

   Commiserations on the Cat front …….. these losses are very hard to bare when they have been a long term family member and one has thus got to know every subtle nuance of their particular character and behavior. Rest in Peace Tara .

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   Daniel Victor

   22 February 2016, 08:25

   I’ll try again.The fact that you picked a white marble makes it impossible that you selected the bag with two black marbles.It also makes it more likely by a factor of 2 to 1 that you chose the bag with 2 white marbles than that you chose the bag with 1 white and 1 black.When you started,there was a 1 in 3 chance of picking any 1 if the three bags,but the marble you have chosen has changed those odds. Suppose,that there was one bag with ten black marbles,one with ten white,and one with just two white and eight black.Now hopefully it is easy to see that if you pick a white marble,it is far more likely that you have selected the bag with ten white marbles than the one with only two white and eight black. My sympathy and commiserations about Tara.

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   Craig SP

   22 February 2016, 08:51

   I remember this one and it’s a total mind fucker. It’s all down to the fact that you would always chose the white marble from Bag C – this is not the case. At the start the probability of picking a white marble is 2/3. That remains the case after one marble has been drawn irrespective of colour. Commiserations for Tara.

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   phil

   22 February 2016, 10:04

   Mr Monk et al is wrong. If he were right it leads to the following concepts.

   The more often you play the national lottery the better the odds are that you will win. That is clearly false

   If inflation inflates a value and deflation deflates one then Mr Monk has it that if an economy is suffering loss of value by deflation then you can recover an economy merely by increasing the rate of deflation, again clearly false.

   Take 100 black balls and 2 white balls, shut you eyes and choose a ball. Mr Monk has it that if you choose a white ball then when you do it again and choose another ball you will have increased your chance of choosing the other white ball merely by choosing the 1st, in reality you reduce your chance of pulling the other white ball not increase it

   There is a game on television whereby you try and win by choosing a high value box , Deal or no deal. Towards the end of the game you are given the choice as to whether you should swap the box. Should you swap the box.

   Let the number of boxes be n, entropy occurred at the rate of n-1 per box (your box is never excluded). Therefore by the time you get to the last box, whole entropy has been used up. Therefore the last choice come totally for free, suffers no entropy and will increase your chances of winning. By reason of entropy you should swap the every time.
   Go check on the internet, someone will have done the algorithm, it will tell you to swap the box, just as I have said you should, I used entropy they will have an algorithmic approach, same outcome..

   Lastly back to the lottery. If Mr Monk was right then on week 2 of the lottery no one would win if that had chosen for week 2 any number the lottery threw up in week 1. Let n be the number of balls in the lottery then Mr Monk has it that on week n+1 no one would ever win a single penny on the lottery ever again no matter how many people played and no matter how long they played

   My answer of 20% is the correct answer

   I am sorry about your cat. I doubt anyone else would have given her the life she had with you and your wife,

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   Shaun

   22 February 2016, 10:52

   this is an age old probability test that seems so intuitively wrong… https://en.m.wikipedia.org/wiki/Bertrand%27s_box_paradox And a similar variant. https://en.m.wikipedia.org/wiki/Monty_Hall_problem

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   Steve Brown

   22 February 2016, 12:49

   Tom,

   Sorry to hear about Tara… that’s a real shame.

   Nevertheless let me, as yet another boring boatie (you’ld never believe I was once a lightweight), try another way of explaining the probability conundrum to you.

   If you think about all the things that can happen then we will end up with six different outcomes,

   We could pick the bag with two black balls and we pick black ball 1 – Outcome 1 (I’m holding a black ball)
   We could pick the bag with two black balls but we pick the other ball – Outcome 2 (I’m holding a black ball)
   We could pick the bag with mixed balls and we pick the black ball – Outcome 3 (I’m holding a black ball)
   We could pick the bag with mixed balls and we pick the white ball – Outcome 4 (I’m holding a white ball)
   We could pick the bag with two white balls and we pick white ball 1 – Outcome 5 (I’m holding a white ball)
   We could pick the bag with two white balls and we pick the other ball – Outcome 6 (I’m holding a white ball)

   So there are three outcomes where we start off holding a white ball and in two of the outcomes we had picked the bag with two white balls. So the chances of that happening is 2/3.

   Does that work… It does feel counter intuitive to not be 50/50 and it made my brain whirl for a bit, but once you have mapped out all the possibilities then it all falls into place.

   Steve

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   Drunken Sailor

   22 February 2016, 14:15

   Shaun,

   The box problem is a different problem as there are 2 distinct draws and therefore a difference between what is found in a particular draw. This is where Monk has gone wrong with his bag problem, where it does not matter which ball is picked out. You cannot equate bags to draws with two halves

   Tom and I are right, Monk – the boring boatie who went to the wrong university and therefore has 2 strikes against him as opposed to Tom, who only has one, as he was not a boring boatie but went to the wrong university, is wrong and should admit it.

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    Warren Buffoon

    22 February 2016, 14:17

    Sorry to here about the cat, it’s good you picked the older cats from the sanctuary, gave them a good quality of life.

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    Striebs

    22 February 2016, 14:23

    Phil ,

    I don’t think that is what Mr Monk is saying .

    The starting point is after the first ball has been chosen .

    Although the two white balls in bag A are identical and indistinguishable , to help solve the problem , treat them as if they are uniquely identifiable .

    Bag-A contains A1W A2W
    Bag-C contains C1W C2B

    Given that you have already chosen a white , there are 3 possibilities for which ball you have already chosen ; it is either A1W , A2W or C1W .

    Thus there are 3 equal possibilities for the ball you will chose next ; A1W,A2W,C2B .

    Therefore only a one in three chance of choosing C2B .

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    bwakem

    22 February 2016, 14:27

    PHIL you are so far off the mark. Once you have selected the first white ball you don’t have any further choice, the second ball is already selected at that point.

    Either:

    1) You have the bag with the black ball in
    2) You have W1 and the other ball is W2
    3) You have W2 and the other ball is W1

    I proved it on the other thread with a 1 million permutation perl program. After a white ball selection the other ball in the same bag is white 66% of the time.

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    Shaz

    22 February 2016, 14:43

    Commiserations about Tara- rest in peace

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    David Russell

    23 February 2016, 03:32

    Sorry about Tara hope you and your wife am OK. We lost Molly last week and its killing me so I do understand. I also remember Kitosh.:)

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    Russ O'Callaghan

    23 February 2016, 05:24

    Sorry to hear about Tara, Tom. I know I’ll feel just the same way when our old tortoiseshell goes. And that cannot be long away now.