{x/x<15 x is a composite counting numbers}

Question

 

A Set is a collection of things (usually numbers).

 

Answer 1

Counting numbers are integers >0.

Composite numbers are non-primes.

The primes between 1 and 15 (discounting 1): 2, 3, 5, 7, 11, 13.

1 is not composite so we can eliminate it, too, leaving {4, 6, 8, 9, 10, 12} as the set of composites between 1 and 15.