Question

If $A=\{1,2,3,4\},B=\{3,4,5,6\}$ and $C=\{1,2,4,6,7\}$ then find $A\cap (B\cap C)$

Answer 1

$B\cap C=\{3,4,5,6\}\cap \{1,2,4,6,7\}$

$=\{4,6\}$

$A\cap (B\cap C)=\{1,2,3,4\}\cap \{4,6\}$

$=\left\{4\right\}$