Newbie Rental Proprties Questions that I'm looking an answer for

[Ali Aldhanhani]

Hello BiggerPockets community, I'm a new newbie to real estate invsesting and in the past few months I have been learning so much about it so I gathered some questions for topics that I did not understand well and I am hoping that you guys can clear them up for me .

1- What does a vacancy mean in a rental property expenses ?

2-How the right amount of a lease gets define in a rental property?

3- What is right way to calculate Annual Return on investment? 

Note! that I have tried my self to calculate the Annual Return on investment with my calculator but it gave me wrong results than that the result mentioned by the book  .