01 Dec 2008, 9:54 pm
Fnord wrote:
The website is wrong. Line up the balls in the following order, from left to right:
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
Ah, but the balls are in a box and you're picking them out at random. You could pick out all the red balls and all the blue balls in the first 12 tries, leaving the three yellow ones, so you would need to pick out 13 to ensure you had one of each colour.
The tulip one - I don't get.
01 Dec 2008, 10:01 pm
Marcia wrote:
Fnord wrote:
The website is wrong. Line up the balls in the following order, from left to right:
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
Ah, but the balls are in a box and you're picking them out at random. You could pick out all the red balls and all the blue balls in the first 12 tries, leaving the three yellow ones, so you would need to pick out 13 to ensure you had one of each colour.
Grr... Aspie mindlock...
The realm of probability includes the equal possibility of either 3 yellow, 5 red, and 1 blue OR 7 blue, 5 red, and 1 yellow. Nowhere in any of the rules was the use of probability theory prohibited. Remember, the minimum number of balls was specified, not the order of the draw!
I guess I've become too used to solving problems by thinking outside the box, especially when there was no box defined.
01 Dec 2008, 10:10 pm
Fnord wrote:
The website is wrong. Line up the balls in the following order, from left to right:
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
Its supposed to be a random pick, worst case scenario.
01 Dec 2008, 10:11 pm
Death_of_Pathos wrote:
Fnord wrote:
The website is wrong. Line up the balls in the following order, from left to right:
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
Its supposed to be a random pick, worst case scenario.
Random pick is stated. Worst case is not. 9 merely has less probability than 13, given all possible permutations.
Quote:
You have 5 red balls, 7 blue balls and 3 yellow balls in a box. You reach in without looking and pull out one ball at a time. What is the fewest number of balls you would need to take out to be sure you took out at least one ball of each color? 3,5,9 or 13
Never assume more than what the stated evidence allows, OR what your own reasoning ability permits.
I'm right. The website is wrong. Plain and simple. You may now bow before my genius.
Last edited by Fnord on 01 Dec 2008, 10:16 pm, edited 1 time in total.
01 Dec 2008, 10:16 pm
01 Dec 2008, 10:17 pm
Death_of_Pathos wrote:
"... to be sure ..."
Assuming you can check the properties of the balls removed, the minimum is 3.
Assuming you can not, the minimum is 13.
Being obstinate doesn't make you right.
Assuming you can check the properties of the balls removed, the minimum is 3.
Assuming you can not, the minimum is 13.
Being obstinate doesn't make you right.
Of course, you are right on both counts.
I bow before YOUR genius!
01 Dec 2008, 10:17 pm
Fnord wrote:
Death_of_Pathos wrote:
Fnord wrote:
The website is wrong. Line up the balls in the following order, from left to right:
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
Its supposed to be a random pick, worst case scenario.
Random pick is stated. Worst case is not. Never assume more than what they evidence allows.
I'm right. The website is wrong. Plain and simple.
What is the FEWEST NUMBER OF BALLS you would need to take out to be sure you took out at least one ball of each color?
i initially thought 9 and still do. it only says fewest and doesn't say both the fewest and the worst.
01 Dec 2008, 10:20 pm
jus4u76 wrote:
Fnord wrote:
Death_of_Pathos wrote:
Fnord wrote:
The website is wrong. Line up the balls in the following order, from left to right:
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
Its supposed to be a random pick, worst case scenario.
Random pick is stated. Worst case is not. Never assume more than what they evidence allows.
I'm right. The website is wrong. Plain and simple.
What is the FEWEST NUMBER OF BALLS you would need to take out to be sure you took out at least one ball of each color?
i initially thought 9 and still do. it only says fewest and doesn't say both the fewest and the worst.
Might want to reconsider that Math major... and to also post stuff like this in the Random forum. Its what its there for.
01 Dec 2008, 10:22 pm
Death_of_Pathos wrote:
jus4u76 wrote:
Fnord wrote:
Death_of_Pathos wrote:
Fnord wrote:
The website is wrong. Line up the balls in the following order, from left to right:
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
3 yellow balls, then 5 red balls, then the 7 blue balls (I did it with marbles, but the same principle applies).
Then you could see graphically that the minimum number of balls required to be picked is 9 IF you pick from left to right. You get the answer of 13 ONLY if you pick from right to left.
Its supposed to be a random pick, worst case scenario.
Random pick is stated. Worst case is not. Never assume more than what they evidence allows.
I'm right. The website is wrong. Plain and simple.
What is the FEWEST NUMBER OF BALLS you would need to take out to be sure you took out at least one ball of each color?
i initially thought 9 and still do. it only says fewest and doesn't say both the fewest and the worst.
Might want to reconsider that Math major... and to also post stuff like this in the Random forum. Its what its there for.
what's wrong with my math skills because im narrow-minded? what can i actually major in if not math? garbage-analysis major?
01 Dec 2008, 10:26 pm
01 Dec 2008, 10:31 pm
As I remember;
The current calendar system has leap years in every year divisible by four, except
for the Centenary years, but only every 400 years (2000 was a leap year, but 1900 was not)
Don't blame me, blame Rome...
01 Dec 2008, 10:33 pm
pakled wrote:
As I remember;
The current calendar system has leap years in every year divisible by four, except
for the Centenary years, but only every 400 years (2000 was a leap year, but 1900 was not)
Don't blame me, blame Rome...
The current calendar system has leap years in every year divisible by four, except
for the Centenary years, but only every 400 years (2000 was a leap year, but 1900 was not)
Don't blame me, blame Rome...
Actually since the year is ~365.24 days long, that is one of the most logical ways to do it.
Basically you had to solve the series {2,1,1,1,2,1,1,1, ...} for the first sum divisible by 7. (365%7=1)
01 Dec 2008, 10:35 pm
01 Dec 2008, 10:40 pm
01 Dec 2008, 10:44 pm
01 Dec 2008, 10:46 pm
