What is the Cartesian product of A={1,2} and B={a,b}?
{(1,1),(2,2),(a,a),(b,b)}
{(1,1),(a,a),(2,a),(1,b)}
{(1,a),(1,b),(2,a),(b,b)}
{(1,a),(2,a),(1,b),(2,b)}
What is the Cartesian product of $A = \left {1, 2\right }$ and $B = \left {a, b\right }$?
$\left {(1, a), (1, b), (2, a), (b, b)\right }$
$\left {(1, 1), (2, 2), (a, a), (b, b)\right }$
$\left {(1, a), (2, a), (1, b), (2, b)\right }$
$\left {(1, 1), (a, a), (2, a), (1, b)\right }$