Question

Write roster and set builder form of "The set of all natural numbers, which divide $42$".

Answer 1

In roster form:

The set of all natural numbers which divide $42$ is denoted by $A:\{1,2,3,6,7,14,21,42\}$

In set builder form:

The set of all natural numbers which divide $42$ is denoted by $A:\{x:x$ is the multiple of $42\}$