Question

Przy danych
a)
P (A') = 1/2
P (A u B) = 2/3
P (A razy B) = 1/3

oblicz :
P( B)
P (A\B)
P (B/A)


b)
P (B')=3/4
P (A u B) = 1/3
P (A razy B) = 1/5

Oblicz:
P(A')
P (A\B)
P (B/A)

Powoli, spokojnie, dokładnie poproszę :)

Answer 1

A)
P(A)=1-P(A')
P(A)=1-1/2=1/2
P(AuB)=P(A)+P(B)-P(AnB)
P(B)=P(AuB)+P(AnB)-P(A)
P(B)=2/3+1/3-1/2=1-1/2=1/2
P(B)=1/2
b)
P(B)=1-3/4=1/4
P(A)=P(AuB)+P(AnB)-P(B)
P(A)=1/3+1/5-1/4=20/60+12/60-15/60=17/60
P(A')=1-17/60=43/60
P(A\B)=P(A)-P(AnB)
P(A\B)=17/60-1/5=17/60-12/60=5/60=1/12
P(B/A)=P(AnB)/P(A)
P(B/A)=1/5 : 17/60=1/5*60/17=12/17

Answer 2

 






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