On my machine it took me a few month to mine a buck of monero, but the slow rate could have been because I can't gpu mine.  i don't bother mining anymore.
  If you have an old pc and want to get started, look into earnhoney.  Many people report making a few bucks a day, and I was too and there wasn't any capchas.  Where I am  am not getting any ads anymore, so i have to use lesser pc based programs that have to be checked every few hours which isn't ideal.

I am getting my first two $20 wifi enabled smartphones on the 15th, and that'll be my first venture into app based passive earning.

If you want to explore it more, try to find on facebook the group thetechslugs
https://www.facebook.com/groups/thetechslugs/?ref=bookmarks