Question 259827
We start with
U = {15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25}, 
A = {16, 18, 20, 22},
B = {17, 19, 20, 23, 24}
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A' = {15, 17, 19, 21, 23, 24, 25}
B' = {15, 16, 18, 21, 22, 25}
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A' n B' = {15, 21, 25}