Answer from cs61c-cf (Aspandiar Dahmubed 16812056) for Question 2
The vending machine - decides what to do depending on how much money is there and what you request
The parking meter - time goes by, it keeps state of how long is still left and accordingly makes changes
Taking an exam :) - I have a state - nervous, cool, casual, shocked with each question and accordingly I decide whether to complete question and be happy or skip and be nervous etc, etc. 
A cat - feed it, its happy; don't feed it, it purrs, don't feed it more, it might die! :(