This is normal. After reading the solution, close the book and re-solve the problem from memory. Then change one number and solve again.

Unlike a textbook, a zbirka is a problem collection. Čolić’s book is organized by topic. For 2nd grade, the core chapters are:

The workbook Zbirka zadataka iz fizike za 2. razred gimnazije (often titled Zadaci i ogledi iz fizike Dr. Ahmed Čolić

Zbirka je prepoznatljiva po svom specifičnom pristupu koji olakšava postepeno usvajanje gradiva: