Suppose that the function f and g are discontinuous at a. Which of the following are true...

i) f+g can never be continuous at a.

ii) 2f can never be continuous at a.

iii) f/g can never be continuous at a.

If it is true give a valid proof, if its false then give a counter example.

Any help would be appreciated. I believe i and ii is true but iii is false but don't quite understand how to show the proof...