csat-suneung 2020 Q9

csat-suneung · South-Korea · csat__math-humanities 3 marks Conditional Probability Direct Conditional Probability Computation from Definitions
A survey was conducted on 200 students at a school regarding their preferences for experiential activities. The students who participated in this survey chose one of cultural experience or ecological research, and the number of students who chose each activity is as follows.
ClassificationCultural ExperienceEcological ResearchTotal
Male Students4060100
Female Students5050100
Total90110200

When one student is randomly selected from the 200 students who participated in this survey and is a student who chose ecological research, what is the probability that this student is a female student? [3 points]
(1) $\frac { 5 } { 11 }$
(2) $\frac { 1 } { 2 }$
(3) $\frac { 6 } { 11 }$
(4) $\frac { 5 } { 9 }$
(5) $\frac { 3 } { 5 }$
A survey was conducted on 200 students at a school regarding their preferences for experiential activities. The students who participated in this survey chose one of cultural experience or ecological research, and the number of students who chose each activity is as follows.

\begin{center}
\begin{tabular}{ | c | c | c | c | }
\hline
Classification & Cultural Experience & Ecological Research & Total \\
\hline
Male Students & 40 & 60 & 100 \\
\hline
Female Students & 50 & 50 & 100 \\
\hline
Total & 90 & 110 & 200 \\
\hline
\end{tabular}
\end{center}

When one student is randomly selected from the 200 students who participated in this survey and is a student who chose ecological research, what is the probability that this student is a female student? [3 points]\\
(1) $\frac { 5 } { 11 }$\\
(2) $\frac { 1 } { 2 }$\\
(3) $\frac { 6 } { 11 }$\\
(4) $\frac { 5 } { 9 }$\\
(5) $\frac { 3 } { 5 }$