Given P = {a, b} and Q = {1, 2}, the cartesian product P × Q is
- {(1, a), (1, b), (2, a), (2, b)}
- {a, b, 1, 2}
- {(a, b), (1, 2)}
- {(a, 1), (b, 1), (a, 2), (b, 2)}
Show answer and solution
Correct answer: D. {(a, 1), (b, 1), (a, 2), (b, 2)}
P × Q is the set of ordered pairs (p, q) with p ∈ P and q ∈ Q. Order matters
P × Q ≠ Q × P in general.