Let a = {x | x = 2n + 1, n ∈ n}, B = {x | 1 ≤ x ≤ 10}, C = {x | x = 3N, n ∈ n}, find (a ∩ b) ∩ C
Set a = {x | x = 2n + 1, n ∈ n} = {1,3,5,7,9 }
So a ∩ B = {1,3,5,7,9}
Set C = {x | x = 3N, n ∈ n} = {0,3,6,9,12 }
So (a ∩ b) ∩ C = {1,3,5,7,9} ∩ {0,3,6,9,12 }={3,9}
Answer: (a ∩ b) ∩ C {3,9}
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