Problem
Let $U=\{1,2,3,4,5,6,7\}, A=\{2,3,5,7\}$, and $B=\{2,4,7\}$. Find the set $A^{\prime} \cap B^{\prime}$. $A^{\prime} \cap B^{\prime}=$ (Use ascending order. Use a comma to separate answers as needed.)
Solution
Step 1 ：A^\prime = U - A = \{1, 4, 6\}
Step 2 ：B^\prime = U - B = \{1, 3, 5, 6\}
Step 3 ：A^\prime \cap B^\prime = \{1, 6\}
Step 4 ：\boxed{\{1, 6\}}
