Probability Theory - conditional

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The discussion revolves around calculating the probability that a tick carries both Lyme disease and human granulocytic ehrlichiosis (HGE). The probabilities provided indicate that 16% of ticks carry Lyme disease and 10% carry HGE, with 10% of ticks that have either disease carrying both. The user is trying to interpret the statement about the percentage of ticks with both diseases, suggesting that P[LH | (L U H)] = 0.1 might be the correct interpretation. There is confusion regarding the calculations, with initial attempts yielding improbably low results. Clarification on how to approach the problem is sought, emphasizing the need for a proper understanding of conditional probabilities.
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Question:
Deer ticks can carry both Lyme disease and human granulocytic ehrilichiosis (HGE). IN a study of ticks in the Midwest, it was found that 16% carried Lyme disease, 10% had HGE, and that 10% of the ticks that had either Lyme disease or HGE carried both diseases.

(a) What is the probability P[LH] that a tick carries both Lyme disease (L) and HGE (H)?

My Part:
I don't know how to interpret this problem. Let me show my work thus far.

P[L] = 0.16
P[H] = 0.1

Now this last part, how do I interpret this..."10% of the ticks that had either Lyme disease or HGE carried both diseases."

Like this? given that the ticks had L or HGE, then the ticks that both diseases. So I would write this as:

P[LH | (L U H)] = 0.1

I don't know if this is right though. Any help would be awesome, thanks!

another thought I had was:
P[LH|L] + P[LH|H] = 0.1

This was the first one I did, but I got a probability of something like 0.006 which seems WAY to low.
 
Last edited:
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P[LH | (L U H)] = 0.1 sounds correct.

It is the probability that a deer has L AND H knowing that it has L OR H. It is basically what the problem is saying but it speaks in percentage of a quantity instead of in probability.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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