c) P ( A ∣ B ) = 10 / 22 .

c) Vì \({\rm{n}}({\rm{A}} \cap {\rm{B}}) = 12,{\rm{n}}({\rm{B}}) = 28\) nên \({\rm{P}}({\rm{A}}\mid {\rm{B}}) = \frac{{{\rm{n}}({\rm{A}} \cap {\rm{B}})}}{{{\rm{n}}({\rm{B}})}} = \frac{{12}}{{28}} \ne \frac{{10}}{{22}}.\)

=> Sai