This is the 2008th most frequent Turkish word.
sorununun
"Your problem's" or "of your problem" (possessive form of "sorun").
Here, 'sorununun' means 'of the problem' helping to show possession referring to the math problem belonging to Ahmet.
Ahmet'in matematik sorununun çözümünü bulduk.
We found the solution to Ahmet's math problem.
In this sentence, 'sorununun' refers to possession, indicating the 'problem' associated with handwriting belongs to 'you'.
Bu defter senin yazım sorununun üstesinden gelmek için alınmış.
This notebook was bought to address your handwriting problem.
Here, 'sorununun' refers to the 'problem' associated with 'skin' belonging to the patient.