M MSkaggs87 New member Joined Sep 2, 2005 Messages 1 Sep 2, 2005 #1 Hey all, Here's my problem: Let A and B be subsets of a universal set U: n(U)=60, n(B)=25, and n(AUB')=45. Find n(AintersectB) and n(A'intersectB). Any ideas?

Hey all, Here's my problem: Let A and B be subsets of a universal set U: n(U)=60, n(B)=25, and n(AUB')=45. Find n(AintersectB) and n(A'intersectB). Any ideas?

S soroban Elite Member Joined Jan 28, 2005 Messages 5,588 Sep 2, 2005 #2 Hello, MSkaggs87! If you sketch a Venn diagram, it may help you follow my reasoning. Let A and B be subsets of a universal set U: n(U)=60, n(B)=25, and n(A U B')=45. Find: n(A ∩ B) and n(A' ∩ B). Click to expand... From DeMorgan's Laws, the complement of A U B' is A' ∩ B Since n(U) = 60 and n(A U B') = 45, then n(A' ∩ B) .= . 60 - 45 .= .15 Since n(B) = 25 and n(A' ∩ B) = 15, then n(A ∩ B) = 10

Hello, MSkaggs87! If you sketch a Venn diagram, it may help you follow my reasoning. Let A and B be subsets of a universal set U: n(U)=60, n(B)=25, and n(A U B')=45. Find: n(A ∩ B) and n(A' ∩ B). Click to expand... From DeMorgan's Laws, the complement of A U B' is A' ∩ B Since n(U) = 60 and n(A U B') = 45, then n(A' ∩ B) .= . 60 - 45 .= .15 Since n(B) = 25 and n(A' ∩ B) = 15, then n(A ∩ B) = 10