Question

Which of the following gives an example of a set that is closed under addition?

The sum of an even number and an even number

The sum of an odd number and an odd number

The sum of a prime number and a prime number

None of these are an example of the closure property

Answer 1

A set is closed under addition if you take any two numbers and the sum is inside that set.

So, for example, the 3rd choice, if you take a prime number and add it to another prime number, the sum is not necessarily a prime number, so it is not closed for addition. Example, the prime number 3 added to the prime number 5, is 8 which is NOT prime.

Go through the choices and select the correct choice.

Answer 2

I got A for my answer. Because an even number + another even number = even number

Answer 3

you are correct