Let B1, B2, B3, B4 be sets with cardinalities given by |Bi| = 3i for 1 <= i <= 4. Calculate the cardinality of the Cartesian product set B1 x B2 x B3 x B4

NOTE: for the B's, the numbers next to them are the little ones, you know?

Basically, is this all I have to do:

B1 has 3 elements, B2 has 6 elements, B3 has 9 elements and B4 has 12 elements thus B1xB2xB3xB4 has 3x6x9x12 = 1,944 elements

Correct or not?