Answer
The set is infinite.
$10$ is not an element of the set.
Work Step by Step
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.