Bro as u might u know there are no of subjects in nda syllabus so in 

Maths there are 30 chapters and 

In english there are 8 topics

In physics chemistry  biology sst and so on.

So bro i believe that i will upload maths ch 1 notes and they will be free and chapter 2 notes will be of 50 rs. And all rest maths chapter will be free but i will upload the maths chapter after chapter 2 only if u buy that chapter notes.

Similarly for each subject 1st will be freee ssecond will be 50 rs and rest will be free.

Decide and tell me i will upload them.

Yes I need it.