-
If S and T are two sets such that S has 21 elements, T has 32 elements, and S ∩ T has 11 elements, how many elements does S ∪ T have?
-
- 52
- 32
- 42
- None of these
Correct Option: C
Given in the question,
n(S) = 21, n(T) = 32, n(S ∩ T) = 11, n(S ∪ T) = ?
Using the formula,
n(S ∪ T) = n(S) + n(T) – n(S ∩ T) = 21 + 32 – 11 = 42
Hence, S ∪ T has 42 elements.
