Answer:
c) Either A or B or both occur.
Step-by-step explanation:
Suppose that we have two events
Event A
Event B
We have that:
In which a a happens and b does not and 
is the probability that aboth events happen
By the same logic, we have that:
The union of events A and B is:
Which includes either one of them or both.
So the correct answer is:
c) Either A or B or both occur.
Answer:
D: a single firm supplies all the output.
Step-by-step explanation:
A natural monopoly runs most efficiently when one large firm supplies all of the output.
A natural monopoly occurs when the most efficient number of firms in the industry is one. As the name suggests, monopoly means single. We can also say that it is a market structure characterized by a single seller, selling a unique product in the market.
Answer:
-1= 1
0= 1
1= 3
2= 5
3= 7
4= 9
5= 11
6= 13
just plug in the numbers for "X"
