A = 1,2,4,5
B = 2,5,3,6
C = 4,5,6,7
U-A-B-C = 8



Rules: U means take them all on the left or right of U
       n means take only what's in common to the left and right of n
       - means take out anything from the set on the left of -
         that's on the right of -.  Don't use any of the ones on
         the right of -.
       ' Don't use any of the set before the ', but use all the others
         in the whole universal set instead.  

a. (A u B)' U C'

(1245 u 2356)' U 4567'
   123456'     U 1238
      78       U 1238
            12378

b. (A- B)' U C

(1245 - 2356)' U 4567
       14'     U 4567
    235678     U 4567
           2345678   


c. A U B'

1245 U 2356'
1245 U 1478
  124578

d. A U ( B n C )

1245 U   56
   12456   

e. A n B n C' 

1245 n 2356 n 4567'
1245 n 2356 n 1238
       2

Edwin