"= Hmm === 
 Ok first off: 
 ""What are the odds that the other side is also black?""    
 I recommend learning the difference between odds and probability. Refer to wikipedia. The odds are 2   

 Now if your asking what is the probability that the other side is black that is 2/3rds.  To those down below that think it is 1/2: the ""trick"" to this is labeling the faces 1 through 6. With 1,2 being the black card, and 3 being the black face of the black/white card. You have been told one of {1,2,3} is showing with equal probability.  What is the probability that the face underneath is one of {1,2,3}.  That probability is 2/3rds. 

 Probability: 
 1/3*1+1/3*1 +1/3*0 = 2/3 

 The odds are (2/3) / (1/3) = 2. 

 I would edit the thread but its just to darn much fun as is. 
    

 :The odds aren't ""2"" but ""2 to 1"". Since such odds aren't stated as simple numbers, there is no danger of confusion between the two formats, which are logically equivalent. And the difference between them is not as interesting as the paradox under discussion. 
 :I like the labeling trick; fortunately it's already in the article. 

 =="