Question

Given A = {8, 9, 10, 12}, B = {2, 3, 4, 5} and the relation R from A to B means : "is multiple of" : find R.

Answer 1

For the Relation $R$ we have to form ordered pairs where $x$ co-ordinate is from set $A$ and is a multiple of $y$ co-ordinate which is from Set $B$.
Since $8$ is a multiple of $2,4$

And $9$ is a multiple of $3$

$10$ is a multiple of $2,5$

$12$ is a multiple of $2,3,4$
We have $R=\left\{\right(8,2),(8,4),(9,3),(10,2),(10,5),(12,2),(12,3),(12,4\left)\right\}$.