What is the maximum sum of these numbers?

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Consider $n$ circles with intersection by any two of them. Any area is all the common part between $m$ circles(a $m$-area): We have $2^n - 1$ areas, $m$ varies between $1$ and $m$.

A $1$-area is an area in a circle with no intersection with the other $n-1$ circles. A place is any surrounded part you can find, a place is different from an area.

The problem is this: Try to put integers in all the places with conditions below: The number in a $1$-area must be less than or equal to $0$, sum of the numbers in any $m$-area can be $0$ or $1$, no place can be empty. What is the maximum sum of the numbers you put in all the places in terms of $n$? Can it be more than $n/2$?!

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Yes, it can be more than $n/2$. I have a counterexample.

Consider three circles, of which each pair intersects each other, but without common intersection. Three circles intersecting

Any two of them have an intersection, but there are six area's, this is less $2^3-1$, so you already made a wrong assumption here, or you forgot a requirement.

Now, put 0's in the 1-area's, and 1's in the 2-area's. All criteria related to your numbers are satisfied. The sum of the numbers is 3, which is clearly greater than 3/2.