(Đúng hay sai) P(B) = P(A).P(B∣A) + P(A).P(B∣A)

Cho các biến cố \(A\), \(B\) thoả mãn \(0 < {\rm{P}}(A) < 1,0 < {\rm{P}}(B) < 1\).

a) $\text{P}\left(B\right)=\text{P}\left(A\right)\cdot \text{P}(B\mid A)+\text{P}\left(\overline{A}\right)\cdot \text{P}(B\mid \overline{A})$