The set of even numbers is closed under addition, the set of odd numbers is not.
That is correct, the set is not closed.
Because the set is not closed under addition. If x and y are odd, then x + y is not odd.
Hennd
The numbers are not closed under addition because whole numbers, even integers, and natural numbers are closed.
The set of even numbers is closed under addition, the set of odd numbers is not.
No. A number cannot be closed under addition: only a set can be closed. The set of rational numbers is closed under addition.
Yes. The set of real numbers is closed under addition, subtraction, multiplication. The set of real numbers without zero is closed under division.
Yes, the set is closed.
That is correct, the set is not closed.
Yes. The empty set is closed under the two operations.
no
no it is not
Yes it is.
If you mean the set of non-negative integers ("whole numbers" is a bit ambiguous in this sense), it is closed under addition and multiplication. If you mean "integers", the set is closed under addition, subtraction, multiplication.
addition
Yes, it is.