If A = {1, 2, 3} and B = {a, b}, find the number of elements in the Cartesian product A × B.
Answer: B
The Cartesian product A × B is the set of all ordered pairs (x, y) such that x ∈ A and y ∈ B.
The number of elements in the Cartesian product is given by n(A × B) = n(A) × n(B).
Here, n(A) = 3 and n(B) = 2.
n(A × B) = 3 × 2 = 6.