How to pass AWS Certified Solutions Architect - Associate ?

Recently my friend Imtiyaz Shaikh passed AWS Certified Solutions Architect - Associate exam. I requested him to write a "how-to-pass-exam" blog but due to his busy schedule, it has not happened.

So I interviewed him on overall exam experience and preparations, do's and don't. This blog is in question answers format.

Q1. How many days are needed for the preparations of this exam?