If n(A) = 3, n(B) = 4, ten write n (A × A × B).

We know ,n(A×B)=n(A)×n(B)


Similarly, n(A×B×C)=n(A)×n(B)×n(C)


Here, n(A)=3 and n(B)=4


n(A×A×C)=n(A)×n(A)×n(B)


=3×3×4


=36


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