Easy notes offer important questions and examination patterns but it would be advised to not rely on the answers or solutions given there. The answers are quite disappointing and irrelevant. You should rather prefer the general textbooks.
However, if the exams are near, you cannot read the textbooks due to time constraints, in this case, you can go for easy notes. They can help you with 25% of your preparation.
Select the important topics and look out for the video lectures on Youtube. It would be advised to buy and follow textbooks especially for Mathematics as the easy notes are not enough.