## Thinking Mathematically (6th Edition)

$III$ region
When we reverse the digits of $9558$, we get $8559$. This means that $9558$ is not a palindromic number. $9558$ is an even number. A - the set of palindromic numbers B - the set of even numbers $9558$ belongs in B but not in A; therefore, it belongs in the region that is inside of the circle for B but not the circle for A: the $III$ region.