student A comes to 80% of the classes while student B comes to 60%, (A,B are independant of one another), on a given day exactly one student arrived, what is the probability that it was student A(adsbygoogle = window.adsbygoogle || []).push({});

P(A)=0.8

P(B)=0.6

P([tex]\bar{A}[/tex])*P(B)=0.12

P([tex]\bar{B}[/tex])*P(A)=0.32

C=> only one student arrived

P(C)=P([tex]\bar{A}[/tex])*P(B) +P([tex]\bar{B}[/tex])*P(A)=0.12 + 0.32 =0.44

P(C/A)=P([tex]\bar{B}[/tex])*P(A)=0.32

P(A/C)=[tex]\frac{P(A)*P(C/A)}{P(C)}[/tex]=[tex]\frac{0.8*0.32}{0.44}[/tex]=0.58

this is wrong the correct answer is meant to be 0.73, any help??

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Class and student probability question

**Physics Forums | Science Articles, Homework Help, Discussion**