# Conditional probability with an uncertain conditional event

#### Buckeye

##### Active Member
You lost me here: "consider that A = red jar and B = black ball, so that the probability tree is telling us that 80% of the jars are red, and that 10% of the balls in the red jars are black, and that 90% of the balls in the other jars are black."

Are your events defined properly? I am confused. Is this just a hypothetical example that you made up? Perhaps it's this mismatch color example that's turning people around?

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#### rothlis

##### New Member
Hmm. I don't see an issue, but I can appreciate how that sentence might be confusing. What if I expanded it to say the following:
"To see how this could apply to our example tree consider that we're using the classic example of drawing balls from jars. A is the "red jar" event, so that the probability tree is telling us that if we randomly select a jar to draw a ball from, there is an 80% chance of drawing from a red jar and a 20% chance of drawing from a non-red jar. B is the "black ball" event, so that the probability tree is telling us that if we draw from a red jar, there is a 10% chance that the ball will be black (and thus a 90% chance that it will be something other than black) and if we draw from a non-red jar, there is a 90% chance that the ball will be black (and thus a 10% chance that it will be something other than black)."

#### rothlis

##### New Member
Bumping this thread to see if anybody is interested in trying to answer the question linked in the original post. It's been 15 months and still nobody has answered it. Or at the very least I could use a few more upvotes on the question to help others find it. Thanks.