Question 1197486: five of 10 new building in a city violate the building code . a random sample of three buildings selected for inspection.
1) what is the probability of none of the building violate the building code in a sample of 3 building .
2) what is the probability of at least one of the new building violate the building code in a sample of 3 building?
Found 2 solutions by ikleyn, ewatrrr:
Answer by ikleyn(52855)   (Show Source):
You can put this solution on YOUR website! .
five of 10 new building in a city violate the building code . a random sample of three buildings selected for inspection.
1) what is the probability of none of the building violate the building code in a sample of 3 building .
2) what is the probability of at least one of the new building violate the building code in a sample of 3 building?
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These two statements are the key input information
"Five of 10 new building in a city violate the building code .
a random sample of three buildings selected for inspection."
But there is no any logic connection between these two sentences.
Therefore, the given post, as it is worded, printed and presented, can not be considered as a Math problem.
What buildings are selected for inspection ?
It is UNCLEAR from the post.
To become a Math problem, this text must be edited and re-written.
But it is not my duty to edit it for you.
In opposite, it is YOUR DUTY to present Math problem clearly and properly.
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I write this addition not for @ewatrrr, because, as I see from her posts, it is IMPOSSIBLE to convince her in something.
The problem is that this text in the post can be interpreted in TWO DIFFERENT WAYS.
One way leads to the Binomial distribution type problem.
The other way lead to hyper-geometric distribution type problem.
Based on the post, it is IMPOSSIBLE to determine correctly,
to which of the two mutually exclusive types this problem does belong.
Therefore, without presenting a right version, a correct solution CAN NOT be presented.
This my note is addressed to the visitor
(in the hope that s/he understand the meaning of these written words)
and/or to the future generation of students who will read these lines.
\\\\\\\\\\\\\\\\\
I just start thinking if it is just the time to write my regular message
to the managers of this project, asking them to remove such " writers "
from the project for their inability to write in mathematically correct way.
If I see similar posts again, I  will send such a message to the managers.
Answer by ewatrrr(24785)  (Show Source):
You can put this solution on YOUR website! p(in-violation) = 5/10 = .5 and p(non-violation) = .5
n = 3
P(non violaltion) = .5^3 = .125
P(at least one in-violation) = 1 - P(none) = 1 - .125 = .875
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