Question 86633
Problem #1
Using the union rule to answer the following questions.

suppose n(A (A LETTER "u" UPSIDE DOWN) b) = 5
        n(A U B) = 35
        n (A) = 13

what is n(B)?
Ans:
 n(A union B) = n(A)+n(B)-n(A intersect B)
   35 = 13 + n(B) - 5
   n(B) = 35-8
   n(B) = 27
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Problem #2
Show that the statements is true by drawing venn diagrams and shading the regions representing the sets on each side of the equals sign.

(A (UPSIDE DOWN U) B)' = A' U B'
Draw two intersecting circles in a rectangle.
Draw it again.
Shade (A intersect B)' in the 1st
Shade (A' union B') in the 2nd
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Do the two shaded areas look the same?
They should. This is one piece of DeMoivre's Rule.
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Cheers,
Stan H.