Do the columns encompass a number of rows, and you need to find the
elements within all those columns / all those rows that adds to 100?

Or does each row have just 4 elements, A, B, C, D, that adds up to a
number in column E greater than 100, and you need to find which of
those 4 elements add to exactly 100?

And how does increasing in intervals of 5 reduce the solution space?