Explanation:
The question is a bit confusing, so I am going to reword it to what I assume it means, which is, “Sergio initially has “p” paintings. There are 12 art collectors total, including Sergio. All the art collectors together donate a total of 48 paintings, and each art collector donates the same number of paintings. How many paintings does Sergio have left?”
p = number of Sergio’s paintings at the start.
p-X = the number of Sergio’s paintings at the end.
48 = the total number of paintings donated by all art collectors
12 = number of art collectors
48/12 = 4 = the number of paintings that each art collector donated
4 = X = the number of paintings that Sergio donated
p-4 = the number of paintings Sergio has left (answer)
(My regrets if my understanding of the question was something other than the above.)