Question

Which of the following sets is an infinite set?
-{1, 2, 3 . . . 100}
-empty set
-the set of whole numbers less than one billion
-the set of natural numbers
-none of the above

Answer 1

infinite set means that we can't count the number of elements.
first set, there are 100 numbers<----counted.
2nd set,0 elements.<-----counted.
3rd set, billion elements<----counted
4th set of natural numbers->infinite.

Answer 2

So it's an empty set?

Answer 3

if we cant count it, then why is it called a countably infinite set?

Answer 4

If something is countable it cant be infinite

Answer 5

@RoxyV16 nopes, empty set has 0 elements,not infinite.
natural numbers is set of infinite numbers.
countably infinite means we can count it in infinite time.