$$\xi=\{1,2,\ldots,15\}.$$ $A$ contains the even numbers in $\xi$. $B$ contains the multiples

Question

$$\xi=\{1,2,\ldots,15\}.$$ $A$ contains the even numbers in $\xi$. $B$ contains the multiples of $3$ in $\xi$. List $A\cap B$. Find $n(A\cap B)$. Describe $A\cap B$ in words.

Accepted Answer

(a) $\{6,12\}$ (b) $2$ (c) Multiples of $6$ in $\xi$

Sets

Sets