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karush
Well-known member
- Jan 31, 2012
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View attachment 1175
(b) $A'=100-30=70$ and since $n(A\cup B) = 65$ and $A+B=80$
then $n(A\cap B)= 15$ so $n(B\cap A')=70+15=85$
(c) $\displaystyle\frac{n(B\cap A')}{n(U)}=\frac{85}{100}=\frac{17}{20}$
or ????
(b) $A'=100-30=70$ and since $n(A\cup B) = 65$ and $A+B=80$
then $n(A\cap B)= 15$ so $n(B\cap A')=70+15=85$
(c) $\displaystyle\frac{n(B\cap A')}{n(U)}=\frac{85}{100}=\frac{17}{20}$
or ????