
### Instruction: help me answer this question We know that n(S) = 21, n(T) = 32, and n(S ∩ T) = 11. Find n(S ∪ T)., think step by step
### Assistant: This is based on the formula n(S ∪ T) = n(S) + n(T) - n(S ∩ T) , The answer is n(S ∪ T) = 21 + 32 - 11 = 42
