Chapter 2 - Set Theory - 2.3 Venn Diagrams and Set Operations - Exercise Set 2.3 - Page 82: 123

$I$ region

When we reverse the digits of $11$ we get $11$. This means that $11$ is a palindromic number. $11$ is not an even number. A - the set of palindromic numbers B - the set of even numbers $11$ Belongs in A but not in B; therefore, it belongs in the region that is inside of the circle for A but not the circle for B: the $I$ region.