How to correctly calculate rental income -cash purchase NEW here

[Lorena Bermudez]

New member!  A family member is about to make an offer on a condo in Orlando for rental investment , this will be paid in cash - both places have renters. 

first one : 

2674 Robert Trent Jones Dr Orlando, FL 32835 - They'll offer 175K ( I think they should offer less )  on the market for 80 days (per Zillow) 

second : 

6025 Westgate Dr 2511, Orlando, FL 32835 - Offering 220 K - in the market for 13 days (per Zillow)

I tried to calculate the rental income but I'm not sure I'm doing this correctly and I would like to give better numbers to help out since it's their first rental purchase. I'm making sure they follow bigger pockets from now on. 

Help please : ) I'm Still learning ...

Lorena