i have deficulty with this three questions that I need to solve and really need help as soon as possible

Question

Let U={w, x, y,1, 2, 3} , A ={2, y} , B = {x, y, 3}, C ={w, y,1}

 

Find AU B'

Find n(B-A) 

find AXB

Answer 1

I assume by B' you mean the complement of B.

A U B' is the union of A and B', thus all members in A and all members in U-B (U-B = {w,1,2}) which is {w, y, 1, 2}

I assume n(P) = the cardinality(number of elements) of P. Then as (B-A) = {x,3} (All elements in B that aren't in A), the cardinality is 2.

AxB is the Cartesian product, which is {(a, b) | a in A and B in B} or {(2,x), (2, y), (2,3), (y, x), (y,y), (y,3)}