Recall the that complements of independent events are also independent.
Let the three mutually independent events be such that .
By the definition of mutually independent events,
Since they are mutually independent events, they are also pairwise e.g.
So, by the distribution property i.e. , then
Then by DeMorgan's Laws,
Since C1, C2, and C3 are mut. ind., then
But from here I do not know how to continue.
Thank you for your time.