2,000,000,000,000
42
There are 33 such numbers.
There are ten such numbers.
27
Infinitely many numbers are below 200.
There are 200.
There are exactly 200 of them.
42
There are 33 such numbers.
There are ten such numbers.
221 and 247 are one of many possible pairs.
27
Infinitely many numbers are below 200.
they have over 200!
200
Many pairs of numbers can add up to 400, such as 200 and 200, or 350 and 50. Additionally, you could have combinations like 100 and 300, or even 0 and 400. The possibilities are virtually endless, as any two numbers that total 400 will suffice.
It is the set of whole numbers from 1 to 200. There is no specific name for such a set.