Set C has 2A + 4Z members and set D has 3B+7Z members.

Question

if they have exactly 3Z members in common how many elements are the union set of c and d disregarding elements that are in the intersection of c and d. 

A)a+b

b)2a+3b

c)2a+3b+5z

d)2a+3b+7z

e)2a+3b+8z

Answer 1

Set C = {A , A , Z, Z , Z , Z}

 

Set D = {B , B , B , Z , Z , Z , Z , Z , Z , Z}

 

 

Both sets have 3 Z's in common.  We take out 2 A and 1 Z from set C.  Take out 3 B and 4 Z from set D.

 

Set C disregards {2A + Z}

Set D disregards {3B + 4Z}

 

 

Set C + Set D = {2A + 3B + 7Z}       are disregarded from the union.

 

 

Answer is (d).

 

 

Hope this helps.