Question on Sets

Question

If set A = {1, 2, 3, 4, 5} and set B = {a, b, c}, what would n(A X B)  be?

 

a. 8

 

b. 11

 

c. 15

 

d. none of the above

Answer 1

AXB is the set of all ordered pairs with the first coordinate in A and the second coordinate in B

note that AxB is not the same as BxA

1a,1b,1c,2a,2b,2c,3a,3b,3c,4a,4b,4c,5a,5b,5c are the elements in the set

15 which is c.

to get the answer just multiply 5*3=15