b) P ( A ∣ B ) = 1 / 3 .
Giải thích
b) \({\rm{P}}({\rm{A}}\mid {\rm{B}}) = \frac{{{\rm{P}}({\rm{A}} \cap {\rm{B}})}}{{{\rm{P}}({\rm{B}})}} = \frac{1}{5}:\frac{2}{5} = \frac{1}{2}.\)
=> Sai
b) \({\rm{P}}({\rm{A}}\mid {\rm{B}}) = \frac{{{\rm{P}}({\rm{A}} \cap {\rm{B}})}}{{{\rm{P}}({\rm{B}})}} = \frac{1}{5}:\frac{2}{5} = \frac{1}{2}.\)
=> Sai