Are you looking for the name of the place value? If you are the answer is ten thousands. If that isn’t what you’re looking for, I need more information.
If

, you have

But if

, you have

So the limit does not exist.
Answer:
(a) {(1, 2), (2,4), (3,6), (4 , 8), (1,3), (3,5), (5,7)}
Step-by-step explanation:
add them