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CUET
Mathematics
Sets
If $n (A) = 10, n (B) = 6$ and $n (C)=5$ for three disjoint sets A, B, C, then $n (A∪B∪C)$ equals
17
21
22
20
The correct answer is Option (2) → 21
Since A, B, C are disjoint sets.
$∴n(A∪B∪C)=n (A) + n (B) + n (C) = 10 +6+5=21$