## Precalculus (6th Edition)

The set is infinite. $10$ is not an element of the set.
The set of natural numbers are the counting numbers $1, 2, 3, ..., 11, 12, 13, ...$. This means that the elements of the given set are $11, 12, 13, ....$. This set has infinite elements. Since the lowest element of the set is $11$, then $10$ is not an element of the given set.