The function

describes a parabola with vertex = (5, 3).
The graph of the function is attached.
10,000,000+2,000,000+
400,000+30,000+90
1 file -> 12 sheets
Now for 3 files -> 3*12 = 36 sheets, it takes up 2/3 of the total
So the total number of sheets: 36 / (2/3) = 54
Your question has been heard loud and clear.
If a and b are two integers , then closure property states that the product of the two integers a and b , which is ab , is also an integer.
Thank you