p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 2Total Golds: 1
Probability: 2
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 3Total Golds: 1
Probability: 1.5
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 3Total Golds: 2
Probability: 1
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 4Total Golds: 2
Probability: 1
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 4Total Golds: 3
Probability: 0.8
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 4Total Golds: 4
Probability: 0.666667
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 5Total Golds: 4
Probability: 0.714286
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 6Total Golds: 4
Probability: 0.75
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 6Total Golds: 5
Probability: 0.666667
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 7Total Golds: 5
Probability: 0.7
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 7Total Golds: 6
Probability: 0.636364
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 7Total Golds: 7
Probability: 0.583333
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 8Total Golds: 7
Probability: 0.615385
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 9Total Golds: 7
Probability: 0.642857
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 9Total Golds: 8
Probability: 0.6
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 10Total Golds: 8
Probability: 0.625
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 10Total Golds: 9
Probability: 0.588235
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 10Total Golds: 10
Probability: 0.555556
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 11Total Golds: 10
Probability: 0.578947
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 12Total Golds: 10
Probability: 0.6
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 12Total Golds: 11
Probability: 0.571429
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 13Total Golds: 11
Probability: 0.590909
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 13Total Golds: 12
Probability: 0.565217
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 13Total Golds: 13
Probability: 0.541667
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 14Total Golds: 13
Probability: 0.56
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 15Total Golds: 13
Probability: 0.576923
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 15Total Golds: 14
Probability: 0.555556
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 16Total Golds: 14
Probability: 0.571429
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 16Total Golds: 15
Probability: 0.551724
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 16Total Golds: 16
Probability: 0.533333
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 17Total Golds: 16
Probability: 0.548387
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 18Total Golds: 16
Probability: 0.5625
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 18Total Golds: 17
Probability: 0.545455
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 19Total Golds: 17
Probability: 0.558824
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 19Total Golds: 18
Probability: 0.542857
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 19Total Golds: 19
Probability: 0.527778
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 20Total Golds: 19
Probability: 0.540541
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 21Total Golds: 19
Probability: 0.552632
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 21Total Golds: 20
Probability: 0.538462
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 22Total Golds: 20
Probability: 0.55
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 22Total Golds: 21
Probability: 0.536585
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 22Total Golds: 22
Probability: 0.52381
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 23Total Golds: 22
Probability: 0.534884
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 24Total Golds: 22
Probability: 0.545455
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 24Total Golds: 23
Probability: 0.533333
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 25Total Golds: 23
Probability: 0.543478
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 25Total Golds: 24
Probability: 0.531915
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 25Total Golds: 25
Probability: 0.520833
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 26Total Golds: 25
Probability: 0.530612
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 27Total Golds: 25
Probability: 0.54
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 27Total Golds: 26
Probability: 0.529412
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 28Total Golds: 26
Probability: 0.538462
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 28Total Golds: 27
Probability: 0.528302
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 28Total Golds: 28
Probability: 0.518519
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 29Total Golds: 28
Probability: 0.527273
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 30Total Golds: 28
Probability: 0.535714
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 30Total Golds: 29
Probability: 0.526316
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 31Total Golds: 29
Probability: 0.534483
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 31Total Golds: 30
Probability: 0.525424
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 31Total Golds: 31
Probability: 0.516667
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 32Total Golds: 31
Probability: 0.52459
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 33Total Golds: 31
Probability: 0.532258
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 33Total Golds: 32
Probability: 0.52381
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 34Total Golds: 32
Probability: 0.53125
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 34Total Golds: 33
Probability: 0.523077
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 34Total Golds: 34
Probability: 0.515152
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 35Total Golds: 34
Probability: 0.522388
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 36Total Golds: 34
Probability: 0.529412
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 36Total Golds: 35
Probability: 0.521739
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 37Total Golds: 35
Probability: 0.528571
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 37Total Golds: 36
Probability: 0.521127
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 37Total Golds: 37
Probability: 0.513889
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 38Total Golds: 37
Probability: 0.520548
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 39Total Golds: 37
Probability: 0.527027
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 39Total Golds: 38
Probability: 0.52
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 40Total Golds: 38
Probability: 0.526316
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 40Total Golds: 39
Probability: 0.519481
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 40Total Golds: 40
Probability: 0.512821
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 41Total Golds: 40
Probability: 0.518987
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 42Total Golds: 40
Probability: 0.525
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 42Total Golds: 41
Probability: 0.518519
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 43Total Golds: 41
Probability: 0.52439
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 43Total Golds: 42
Probability: 0.518072
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 43Total Golds: 43
Probability: 0.511905
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 44Total Golds: 43
Probability: 0.517647
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 45Total Golds: 43
Probability: 0.523256
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 2 p3s1: 1 p3s2: 1
Total Browns: 45Total Golds: 44
Probability: 0.517241
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 2 p3s1: 2 p3s2: 1
Total Browns: 46Total Golds: 44
Probability: 0.522727
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 2 p2s2: 1 p3s1: 2 p3s2: 2
Total Browns: 46Total Golds: 45
Probability: 0.516854
-------------------------------------------------------
p1s1: 2 p1s2: ->1<- p2s1: 1 p2s2: 2 p3s1: 1 p3s2: 2
Total Browns: 46Total Golds: 46
Probability: 0.511111
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 1 p2s2: 1 p3s1: 2 p3s2: 1
Total Browns: 47Total Golds: 46
Probability: 0.516484
-------------------------------------------------------
p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2
Total Browns: 48Total Golds: 46
Probability: 0.521739
-------------------------------------------
A real mind bender
Author
On our biology final test, we were asked the final question for extra credit:
There are three pancakes in a hat. One pancake is golden on both sides, one is brown on both sides, and the last is gold on one side and brown on the other. You draw one pancake from the hat and the side you see is brown. What's the probability the other side of the pancake you drew is brown?
Most people in my class (including me) figgured it was 1/2 but the teacher told is it was 2/3.
I decided to write a program testing this by randomly setting up the pancake sides and checking the other side of the "drawn" one. However, It's showing the probibility as being ~50% (determined by dividing the number of pancakes with brown on the other side by the total number of pancakes checked.)
Here's some of the results it's been giving me (p1s1 stands for pancake 1 side 1 and p1s1 will always be 2 representing the brown side I drew. Program checks pancake 1 side 2 to see what color it is).
1 = gold, 2 = brown
ah
the trick here is that you are picking sides of a pancake, not a whole pancake. so if you''ve picked a brown side, there are 3 respective sides that can be on the other side, one gold and 2 browns. so there is 2/3 a chance for brown being on the other side....
make sense?
-me
the trick here is that you are picking sides of a pancake, not a whole pancake. so if you''ve picked a brown side, there are 3 respective sides that can be on the other side, one gold and 2 browns. so there is 2/3 a chance for brown being on the other side....
make sense?
-me
The fact that you are picknig side''s, and not whole pancakes, is irrelevant. It''s pretty apparent to me that a pancake would have to have two sides. You are looking at the other side of the pancake you drew.
Palidine''s got it - you''re probably counting whole gold pancakes that you got out of the hat.
Since you already know that the pancake you have has at least one brown side, you know you are holding one of only three possible pancakes - and in that set, two will have the other side brown, one will have it golden, hence, a 2/3 probability of the other side also being brown.
Since you already know that the pancake you have has at least one brown side, you know you are holding one of only three possible pancakes - and in that set, two will have the other side brown, one will have it golden, hence, a 2/3 probability of the other side also being brown.
Author
Now I''m getting a bit confused :\
The count of gold pancakes taken out of the hat shouldn''t be realivent to the predicted probability.
However, I''m beginning to think there''s something wrong with my random number generator. If you search the string "p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2" in the results, you''ll see it comes up every three result-sample-thinggies. Maybe I should only seed the random number generator once in the program?
The count of gold pancakes taken out of the hat shouldn''t be realivent to the predicted probability.
However, I''m beginning to think there''s something wrong with my random number generator. If you search the string "p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2" in the results, you''ll see it comes up every three result-sample-thinggies. Maybe I should only seed the random number generator once in the program?
The way a problem is structured is very determining of how it should be solved.
The correct answer is of course 1/2, no matter what everyone tells you.
You teacher is just trying to make herself look smarter by pulling some basic Math trick.
When you get the test back can you post the *exact* phrasing of the question? That is very important. If it was as you said in your original post, then I stand by my answer.
The result 2/3 falls outside of the Universe of the result:
"What is the probability that the OTHER side is also brown".
That sentence defines our Universe as:
U = {Brown-Brown; Brown-Gold}
The Gold-Gold pancake doesnt even make it into the problem, because it fails to pass the universe analisis test, a basic step in probability solving your math teacher should know about.
[Hugo Ferreira][Positronic Dreams][Colibri 3D Engine][Entropy HL2 MOD]
[Yann L.][Enginuity] [Penny Arcade] [MSDN][VS RoadMap][Humus][BSPs][UGP][NeHe]
"I say we take off and nuke the entire site from orbit. It''s the only way to be sure."
The correct answer is of course 1/2, no matter what everyone tells you.
You teacher is just trying to make herself look smarter by pulling some basic Math trick.
When you get the test back can you post the *exact* phrasing of the question? That is very important. If it was as you said in your original post, then I stand by my answer.
The result 2/3 falls outside of the Universe of the result:
"What is the probability that the OTHER side is also brown".
That sentence defines our Universe as:
U = {Brown-Brown; Brown-Gold}
The Gold-Gold pancake doesnt even make it into the problem, because it fails to pass the universe analisis test, a basic step in probability solving your math teacher should know about.
[Hugo Ferreira][Positronic Dreams][Colibri 3D Engine][Entropy HL2 MOD][Yann L.][Enginuity] [Penny Arcade] [MSDN][VS RoadMap][Humus][BSPs][UGP][NeHe]
"I say we take off and nuke the entire site from orbit. It''s the only way to be sure."
quote:Original post by Palidine
the trick here is that you are picking sides of a pancake, not a whole pancake. so if you''ve picked a brown side, there are 3 respective sides that can be on the other side, one gold and 2 browns. so there is 2/3 a chance for brown being on the other side....
make sense?
That doesn''t make sense to me. If you''ve picked a pancake with a brown side up, then there are only 2 possibilities that fit (brown on both sides or brown on only the side you see). The 3rd is impossible since it can''t be gold on both sides and have a brown side up at the same time.
quote:Original post by alexmoura
Palidine''s got it - you''re probably counting whole gold pancakes that you got out of the hat.
Since you already know that the pancake you have has at least one brown side, you know you are holding one of only three possible pancakes - and in that set, two will have the other side brown, one will have it golden, hence, a 2/3 probability of the other side also being brown.
If you already no one side is brown, how can two in that set have the other side brown? That would mean there are two pancakes that are brown on both sides.
I think 50% sounds right. Given that you are holding a pancake with one side brown, what are the odds that the other side is brown too? There are only 2 pancakes that you can hold that have brown on one side. And of those only 1 is brown on both sides so 1/2.
Tadd
- WarbleWare
quote:Original post by Xtremehobo
However, I''m beginning to think there''s something wrong with my random number generator. If you search the string "p1s1: 2 p1s2: ->2<- p2s1: 2 p2s2: 1 p3s1: 1 p3s2: 2" in the results, you''ll see it comes up every three result-sample-thinggies. Maybe I should only seed the random number generator once in the program?
that''s correct, you should only seed the random numbers once in the program
If you call the pancakes bb, bg, and gg, the theory behind 50/50 odds is that bb and bg will be chosen with equal probability, so half the time the opposite side is brown, and half the time its golden... The problem with this reasoning is that half the time you choose bg, the side you see is gold so you don''t even bother checking the other side (it doesn''t count toward your result). But EVERY time you select bb, it counts toward your results. So bb constitutes twice as many entries in your result set as bg, so the answer is 2/3.
This topic is closed to new replies.
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