Question 1117933: Question 921226: From a city 3 newspapers A, B, C are being published. ‘A’ is read by 20%, ‘B’ is read by 16%, and
‘C’ is read by 14%, both A and B are read by 8%, both A and C are read by 5%, both B and C are read by 4% and all three A, B, C are read by 2%. What is the percentage of the population that read at least one paper?
Answer by ikleyn(52879)   (Show Source):
You can put this solution on YOUR website! .
You are given 3 sub-sets A, B and C of a "universal" set.
You know that P(A) = 20%, P(B) = 16%, P(C) = 14%,
P(AnB) = 8%, PAnC) = 5%, PBnC) = 4%,
P(AnBnC) = 2%,
and they want you to find P(A U B U C).
In this situation, the formula works
P(A U B U C) = P(A) + P(B) + P(C) - P(AnB) - P(AnC) - P(BnC) + P(anBnC) =
20% + 16% + 14% - 8% - 5% - 4% + 2% = 35%.
Answer. 35%.
For details and better understanding, see the lessons
- Counting elements in sub-sets of a given finite set
- Advanced problems on counting elements in sub-sets of a given finite set
in this site.
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