Question 1089977: An urn contained 6 white balls and 5 black balls. Two of the white balls and one of the black balls are rough. What is the probability of drawing a ball that is either rough or white?
--I am going to attempt to solve this but I figure I'd ask for help just to make sure I get the correct answer.
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! 4 WS, white and smooth.
2 WR, white and rough
4 BS, black and smooth
1 BR, black and rough.
Looking at these, rough or white is the first, second and the fourth or 7/11.
Another way to look at it is NOT black and smooth (both), which is 1-4/11
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