the questions i have to ask i believe have a similar process which is why i have grouped them together:
Sets P and Q; |P|= 6, |Q|= 15 and |P 'AND' Q| = 5; what's |Q\P|
I know the answers is 10, I'm just not sure that my method was correct as i was trying to figure out the process from the answer; at first i did 15-5 then 15-6+1 but I'm sure its incorrect
each set X and Y contain 19 elements, then the maximum number of elements in the set
(X 'OR' Y)\Y (answer 19)
each set P and Q contains 40 elements; the maximum number of elements in the set
P 'OR' (Q\P) (answer 80)
If anyone can help that would be appreciated; i think i am confusing myself by trying to think of the elements themselves rather than how many of them there are and I am not sure how to adapt counting principles to these questions.