Iran, there’s no way I can answer that! It’s a matter of individuals, their motivation, the other distractions in their lives, the amount of time per day, per week that you have available and that you’re willing to invest, your ability to absorb new issues ……..
So many variables so no possibility of being able to answer you
What I can suggest is that you invest in a revision kit /exam kit and work through the questions in there over and over and over again
And DON’T write your answers / guesses in the book. That way you won’t affect your repeated practice by any previous attempts