Question

sendo P(A)=1/2, P(B)=1/3 e P(A e B)=1/6, calcule P(AUB), P(A), P(B), ....

Answer 1

p(a/b)= p(AinterceçãoB)/p(b) 
p(aUb)= p(a) + p(b) - p(A inter B); 
ajusta ai e dá: 
p(A inter B) = p(a) + p(b) - p(A U B) 
p(A inter B) = 1/3 + 3/4 - 11/12 = 2/12 

p(a/b)= (2/12)/(3/4)= 8/36 = 2/9 = 22,2%