In a poll of 200 people who answered either yes or no to each of two q
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21 Apr 2023, 14:42
You have 200 people and in the first round 170 say YES and, therefore, 30 say NO.
In the second round, you still have 200 people BUT you have always two groups.
Composed of 170 and the rest, 30 people.
10 say YES therefore 160 say NO.
AND the other group of 30 people, in which 10 say YES and 20 say NO
Taking together, both say NO in the first round are 30 and in the second are 20.
The people who say both NO are between 20 and 30
\(20 \leq \) NO \(\leq 30\)
C and D are the answers