Let U={1,2,…,15}U = \{1, 2, \dots, 15\}U={1,2,…,15}. Let A={x∈U∣xextisamultipleof2}A = \{x \in U \mid x ext{ is a multiple of } 2\}A={x∈U∣xextisamultipleof2}, B={x∈U∣xextisamultipleof3}B = \{x \in U \mid x ext{ is a multiple of } 3\}B={x∈U∣xextisamultipleof3}, and C={x∈U∣xextisamultipleof5}C = \{x \in U \mid x ext{ is a multiple of } 5\}C={x∈U∣xextisamultipleof5}. Find the cardinality of the set (A∪B∪C)′(A \cup B \cup C)'(A∪B∪C)′.
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