Menu

Home › Forums › Other › The movie 21 Please explain the math.

Viewing 15 posts - 16 through 30 (of 221 total)
1 2 3 … 13 14 15
  • Author
    Posts
  • July 25, 2008 at 10:24 PM #247461
    Eugene
    Participant

    No, because it’s possible that the car is behind the door that the player picked initially.

    July 25, 2008 at 11:18 PM #247264
    sdnativeson
    Participant

    We have a contestant we’ll call him ‘TheBreeze’ aka
    ‘TB’.
    TB choses door #1, the probability that TB chose the door with the car is 1/3 and, the probability that it is behind one of the other doors is 2/3. By showing TB one of doors #2 or #3 which does not hide the car but a goat (#2 for instance), the host is giving TB an good idea of what is behind those two doors. The probability is still 2/3 that one of them hides the car, but now you know which of the two it would be: Door 3.

    The probability is still only 1/3 that the car is behind Door 1, but 2/3 that it is behind Door 3.

    Anyone remember “Lets Make a Deal”?

    July 25, 2008 at 11:18 PM #247417
    sdnativeson
    Participant

    We have a contestant we’ll call him ‘TheBreeze’ aka
    ‘TB’.
    TB choses door #1, the probability that TB chose the door with the car is 1/3 and, the probability that it is behind one of the other doors is 2/3. By showing TB one of doors #2 or #3 which does not hide the car but a goat (#2 for instance), the host is giving TB an good idea of what is behind those two doors. The probability is still 2/3 that one of them hides the car, but now you know which of the two it would be: Door 3.

    The probability is still only 1/3 that the car is behind Door 1, but 2/3 that it is behind Door 3.

    Anyone remember “Lets Make a Deal”?

    July 25, 2008 at 11:18 PM #247424
    sdnativeson
    Participant

    We have a contestant we’ll call him ‘TheBreeze’ aka
    ‘TB’.
    TB choses door #1, the probability that TB chose the door with the car is 1/3 and, the probability that it is behind one of the other doors is 2/3. By showing TB one of doors #2 or #3 which does not hide the car but a goat (#2 for instance), the host is giving TB an good idea of what is behind those two doors. The probability is still 2/3 that one of them hides the car, but now you know which of the two it would be: Door 3.

    The probability is still only 1/3 that the car is behind Door 1, but 2/3 that it is behind Door 3.

    Anyone remember “Lets Make a Deal”?

    July 25, 2008 at 11:18 PM #247480
    sdnativeson
    Participant

    We have a contestant we’ll call him ‘TheBreeze’ aka
    ‘TB’.
    TB choses door #1, the probability that TB chose the door with the car is 1/3 and, the probability that it is behind one of the other doors is 2/3. By showing TB one of doors #2 or #3 which does not hide the car but a goat (#2 for instance), the host is giving TB an good idea of what is behind those two doors. The probability is still 2/3 that one of them hides the car, but now you know which of the two it would be: Door 3.

    The probability is still only 1/3 that the car is behind Door 1, but 2/3 that it is behind Door 3.

    Anyone remember “Lets Make a Deal”?

    July 25, 2008 at 11:18 PM #247485
    sdnativeson
    Participant

    We have a contestant we’ll call him ‘TheBreeze’ aka
    ‘TB’.
    TB choses door #1, the probability that TB chose the door with the car is 1/3 and, the probability that it is behind one of the other doors is 2/3. By showing TB one of doors #2 or #3 which does not hide the car but a goat (#2 for instance), the host is giving TB an good idea of what is behind those two doors. The probability is still 2/3 that one of them hides the car, but now you know which of the two it would be: Door 3.

    The probability is still only 1/3 that the car is behind Door 1, but 2/3 that it is behind Door 3.

    Anyone remember “Lets Make a Deal”?

    July 26, 2008 at 8:19 AM #247334
    Coronita
    Participant

    duplicate deleted

    July 26, 2008 at 8:19 AM #247489
    Coronita
    Participant

    duplicate deleted

    July 26, 2008 at 8:19 AM #247493
    Coronita
    Participant

    duplicate deleted

    July 26, 2008 at 8:19 AM #247550
    Coronita
    Participant

    duplicate deleted

    July 26, 2008 at 8:19 AM #247556
    Coronita
    Participant

    duplicate deleted

    July 26, 2008 at 8:22 AM #247339
    Coronita
    Participant

    [quote]We have a contestant we’ll call him ‘TheBreeze’ aka
    ‘TB’.
    TB choses door #1, the probability that TB chose the door with the car is 1/3 and, the probability that it is behind one of the other doors is 2/3. By showing TB one of doors #2 or #3 which does not hide the car but a goat (#2 for instance), the host is giving TB an good idea of what is behind those two doors. The probability is still 2/3 that one of them hides the car, but now you know which of the two it would be: Door 3.

    The probability is still only 1/3 that the car is behind Door 1, but 2/3 that it is behind Door 3.

    Anyone remember “Lets Make a Deal”?
    [/quote]

    Also known as the Monty Hall problem, an example of conditional probability.
    http://en.wikipedia.org/wiki/Monty_Hall_problem
    http://en.wikipedia.org/wiki/Conditional_probability

    You can literally count the outcomes if you need to and figure out your odds are better if you switch to avoid the mathematical proof.

    July 26, 2008 at 8:22 AM #247494
    Coronita
    Participant

    [quote]We have a contestant we’ll call him ‘TheBreeze’ aka
    ‘TB’.
    TB choses door #1, the probability that TB chose the door with the car is 1/3 and, the probability that it is behind one of the other doors is 2/3. By showing TB one of doors #2 or #3 which does not hide the car but a goat (#2 for instance), the host is giving TB an good idea of what is behind those two doors. The probability is still 2/3 that one of them hides the car, but now you know which of the two it would be: Door 3.

    The probability is still only 1/3 that the car is behind Door 1, but 2/3 that it is behind Door 3.

    Anyone remember “Lets Make a Deal”?
    [/quote]

    Also known as the Monty Hall problem, an example of conditional probability.
    http://en.wikipedia.org/wiki/Monty_Hall_problem
    http://en.wikipedia.org/wiki/Conditional_probability

    You can literally count the outcomes if you need to and figure out your odds are better if you switch to avoid the mathematical proof.

    July 26, 2008 at 8:22 AM #247498
    Coronita
    Participant

    [quote]We have a contestant we’ll call him ‘TheBreeze’ aka
    ‘TB’.
    TB choses door #1, the probability that TB chose the door with the car is 1/3 and, the probability that it is behind one of the other doors is 2/3. By showing TB one of doors #2 or #3 which does not hide the car but a goat (#2 for instance), the host is giving TB an good idea of what is behind those two doors. The probability is still 2/3 that one of them hides the car, but now you know which of the two it would be: Door 3.

    The probability is still only 1/3 that the car is behind Door 1, but 2/3 that it is behind Door 3.

    Anyone remember “Lets Make a Deal”?
    [/quote]

    Also known as the Monty Hall problem, an example of conditional probability.
    http://en.wikipedia.org/wiki/Monty_Hall_problem
    http://en.wikipedia.org/wiki/Conditional_probability

    You can literally count the outcomes if you need to and figure out your odds are better if you switch to avoid the mathematical proof.

    July 26, 2008 at 8:22 AM #247555
    Coronita
    Participant

    [quote]We have a contestant we’ll call him ‘TheBreeze’ aka
    ‘TB’.
    TB choses door #1, the probability that TB chose the door with the car is 1/3 and, the probability that it is behind one of the other doors is 2/3. By showing TB one of doors #2 or #3 which does not hide the car but a goat (#2 for instance), the host is giving TB an good idea of what is behind those two doors. The probability is still 2/3 that one of them hides the car, but now you know which of the two it would be: Door 3.

    The probability is still only 1/3 that the car is behind Door 1, but 2/3 that it is behind Door 3.

    Anyone remember “Lets Make a Deal”?
    [/quote]

    Also known as the Monty Hall problem, an example of conditional probability.
    http://en.wikipedia.org/wiki/Monty_Hall_problem
    http://en.wikipedia.org/wiki/Conditional_probability

    You can literally count the outcomes if you need to and figure out your odds are better if you switch to avoid the mathematical proof.

  • Author
    Posts
Viewing 15 posts - 16 through 30 (of 221 total)
1 2 3 … 13 14 15
  • You must be logged in to reply to this topic.