Wrong results on count and sum on table

Hello to all,
I am uploading a self-explanatory file where I am getting wrong results on counting and summing data from a table. I think it is because of the use of FILTER inside the sum. Searched the web but found no solution.
Can someone please give me a hand on this?
Many thanks,
Octavio

For Q8 try

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For R8

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and S8

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