Suppose U={x∈Z+∣x<40}, A={multiples of 4 less than 40}, B={multiples of 6 less than 40}, and C={multiples of 12 less than 40}.
(1) List the sets A, B, and C.
(2) Find:
iA∩B
iiB∩C
iiiA∩C
ivA∩B∩C
vA∪B∪C
(3) Show that n(A∪B∪C)=n(A)+n(B)+n(C)−n(A∩B)−n(B∩C)−n(A∩C)+n(A∩B∩C).