The question goes like this: Let $A_1,A_2 , A_3 $ be events with probabilities $\frac15$, $\frac14, and \frac13$ respectively. Let N be the number of these events that occur. Write down a formula for N in terms of indicators.
I am confused on 2 parts. Firstly, I'm not sure what this problem is saying about the 3 events. Does it sound like it's saying the probabilities of $A_1,A_2 , A_3 $ happening all at the same time is the listed probabilities? And then secondly how would we come up with a formula for the number of times these events occur. I would say $N={1,2,3,...,N}$ but that cant be right.