Question 1182919

I have been struggling with this problem for a few days now: 

Let
U	 = 	{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
A	 = 	{1, 2, 4, 6}
B	 = 	{3, 7}
C	 = 	{1, 3, 6, 7, 9}
List all the members of the following set. 
A ∩ (B ∪ C)

The class I am taking has no textbooks to reference, so I have been trying to figure this out on my own. I found a similar question with a similar set (where the places of A and C were swapped in the set) on this website, and so I tried the solution and got this as my final answer:
3,6,7

The solution basically suggested that you combine the numbers and drop all duplicates (the solution I followed ignores all members of U and only used A, B, and C members).
The answer, however, is incorrect. 

I am stumped and would appreciate any tips. Thank you!
So
<pre>Yes, elements in set U are NOT factored into your answer for: A ∩ (B ∪ C)
A ∩ (B ∪ C)
∪ INDICATES UNION, which is: ALL ELEMENTS in BOTH sets, EXCLUDING DUPLICATES
             A ∩ [B + C  -  (B ∩ C)]
             A ∩ (ALL in BOTH sets, or ALL in B & C, EXCLUDING DUPLICATES)
        A      ∩ (ALL in B + ALL in C, less ELEMENTS in BOTH B & C)
  (1, 2, 4, 6) ∩ [(3, 7) + (1, 3, 6, 7, 9)  -  (3, 7)]
  (1, 2, 4, 6) ∩ (1, 3, 6, 7, 9)
  A ∩ (B ∪ C) = {{{highlight_green(matrix(1,2, "(1,", "6)"))}}}