Question

lf A= {3, 5, 7, 9, 11}, B={7, 9, 11, 13 }, C={11, 13, 15} and D={15, 17 }; find $A \cap B$

Answer 1

we know, if two sets A and B are given then, intersection of A and B is the set of all distinct elements that are in both A and B. it is denoted by $A\cap B$ or $B\cap A$. in figure, shaded region indicates $A\cap B$.

now come to the question,
here given, A= {3, 5, 7, 9, 11}, B={7, 9, 11, 13 }, C={11, 13, 15} and D={15, 17 }
we have to find $A\cap B$
so, $A\cap B$ = {3, 5, 7, 9, 11} $\cap$ {7, 9, 11, 13} = {7, 9, 11}