Question

A set $X$ representing all the multiples of $3$ greater than $3$ can be written in the roster form as .

• A. $X=\{6,9,12,15\}$
• B. $X=\{6,9,12,15,...\}$
• C. $X=\{3,6,9,12,15\}$

Answer 1

The correct option is B $X=\{6,9,12,15,...\}$

The set $X$ represents all multiples of $3$ greater than $3.$
We know the multiples of $3$ greater than $3$ are $6,9,12,15,...$

Since, the elements can go upto infinity, we will use ellipsis or three dots to signify elements going upto infinity.
Hence, In roster form $X$ can be represented as:
$X=\{6,9,12,15,...\}$