Hey guys just having some trouble with set notation.

A survey is classified as successful if usable data is obtained from it. Let Ai denote the event that at mostirepetitions of the survey are required for success. Use set notation to identify the following events:

a) Exactly 1 repetition is required for success

b) At least 2 repetitions are required for success,

c) At least i (where i ≥2) repetitions are required for success

d) Exactly i (where i ≥2) repetitions are required for success

e) Is it true that A1OR A2 = A2?

f) What then is A1AND A2AND A3?

Ok so I am pretty sure that e is true because A1 is a proper subset of A2? Therefore the union of them would be equal to just the elements of A2

For a I know that A1 is a subset of all the successive sets and so I would need to negate the subsets from the subsequent sets but I am not sure how to do this. Something along the lines of Ai = (i:i=1)? A friend of mine said something about A1 OR (A0)c

For b I am not sure at all the best I could do was A2OR…Ai = (i:i>2)

For c it might be Big ORi Ai = (i:i≥2)

D and f I don’t really have any idea.

I know the difference between exactly and at least but am not sure how to apply it in this problem. I have this horrible feeling that everything I just wrote is wrong haha

If someone could steer me in the right direction that would be great.

(I’m new to set notation) Should there be a different variable in the brackets?