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| Question 191247:  Several of us in class are having problems with sets, subsets, etc. This question was placed on the board for us to solve.  I so need help with this please.
 Given U = {All letters of the alphabet}, A = {c, d, e, f}, and B = {e, f, g, h, k}.  List the elements of set
 (a) A U B
 (b) A ∩ B
 (c) A′ ∩ B′
 (d) A′ U B′
 (e) A U B′
 (f) (A U B′) ∩ B
 (g) (A U B) ∩ (A U B′)
 
 Answer by user_dude2008(1862)
      (Show Source): 
You can put this solution on YOUR website! If U = {All letters of the alphabet}, A = {c, d, e, f} and B = {e, f, g, h, k}, then 
 A' = {a, b, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z}
 
 and
 
 B' = {a, b, c, d, i, j, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z}
 
 A': set with members that are in U but not in A
 
 B': set with members that are in U but not in B
 
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 a) Combine sets A & B (take out duplicates)
 A U B = {c, d, e, f, g, h, k}
 
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 b) Find common elements in sets A & B
 A ∩ B = {e, f}
 
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 c) Find common elements in sets A' & B'
 A′ ∩ B′ = {a, b, i, j, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z}
 
 
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 (d) Combine sets A' & B' (take out duplicates)
 
 A′ U B′ = {a, b, c, d, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z}
 
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 (e)  Combine sets A & B'
 A U B′ = {a, b, c, d, e, f, i, j, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z}
 
 
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 (f) Hint: use part e)
 (A U B′) ∩ B = {a, b, c, d, e, f, i, j, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z} ∩ {e, f, g, h, k}
 
 (A U B′) ∩ B = {e, f}
 
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 (g) (A U B) ∩ (A U B′)
 
 hint: use parts a) and e)
 
 (A U B) ∩ (A U B′) = {c, d, e, f, g, h, k} ∩ {a, b, c, d, e, f, i, j, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z}
 
 
 (A U B) ∩ (A U B′) = {c, d, e, f}
 
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