isi-entrance 2020 Q21

isi-entrance · India · UGA Conditional Probability Bayes' Theorem with Diagnostic/Screening Test
Shubhaangi thinks she may be allergic to Bengal gram and takes a test that is known to give the following results:
  • For people who really do have the allergy, the test says ``Yes'' $90 \%$ of the time.
  • For people who do not have the allergy, the test says ``Yes'' $15 \%$ of the time.
If $2 \%$ of the population has the allergy and Shubhaangi's test says ``Yes'', then the chances that Shubhaangi does really have the allergy are
(A) $1 / 9$
(B) $6 / 55$
(C) $1 / 11$
(D) cannot be determined from the given data. 
Shubhaangi thinks she may be allergic to Bengal gram and takes a test that is known to give the following results:
\begin{itemize}
  \item For people who really do have the allergy, the test says ``Yes'' $90 \%$ of the time.
  \item For people who do not have the allergy, the test says ``Yes'' $15 \%$ of the time.
\end{itemize}
If $2 \%$ of the population has the allergy and Shubhaangi's test says ``Yes'', then the chances that Shubhaangi does really have the allergy are\\
(A) $1 / 9$\\
(B) $6 / 55$\\
(C) $1 / 11$\\
(D) cannot be determined from the given data.
Paper Questions
Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 Q19 Q20 Q21 Q22 Q23 Q24 Q25 Q26 Q27 Q28 Q29 Q30