csat-suneung 2006 Q26

csat-suneung · South-Korea · csat__math-humanities 3 marks Conditional Probability Direct Conditional Probability Computation from Definitions
A certain class consists of 18 male students and 16 female students. All students in this class take a class in either Chinese or Japanese, but not both. Among the male students, 12 take Chinese class, and among the female students, 7 take Japanese class. When a student selected from this class is taking Chinese class, what is the probability that this student is female? [3 points]
(1) $\frac { 1 } { 7 }$
(2) $\frac { 2 } { 7 }$
(3) $\frac { 3 } { 7 }$
(4) $\frac { 4 } { 7 }$
(5) $\frac { 5 } { 7 }$
A certain class consists of 18 male students and 16 female students. All students in this class take a class in either Chinese or Japanese, but not both. Among the male students, 12 take Chinese class, and among the female students, 7 take Japanese class. When a student selected from this class is taking Chinese class, what is the probability that this student is female? [3 points]\\
(1) $\frac { 1 } { 7 }$\\
(2) $\frac { 2 } { 7 }$\\
(3) $\frac { 3 } { 7 }$\\
(4) $\frac { 4 } { 7 }$\\
(5) $\frac { 5 } { 7 }$