Total possible cases 12C3
\(=\frac{12\times11\times10\times9!}{3!\times9!}=220\) ways
Total ways of selecting three non-defective bulbs
\(=\) 8C3\(=\frac{8\times7\times6\times5!}{3!\times5!}=56\)
Required probability \(=\frac{56}{220}=\frac{14}{55}\)
The correct option is (A)
Based upon the results of regular medical check-ups in a hospital, it was found that out of 1000 people, 700 were very healthy, 200 maintained average health and 100 had a poor health record.
Let \( A_1 \): People with good health,
\( A_2 \): People with average health,
and \( A_3 \): People with poor health.
During a pandemic, the data expressed that the chances of people contracting the disease from category \( A_1, A_2 \) and \( A_3 \) are 25%, 35% and 50%, respectively.
Based upon the above information, answer the following questions:
(i) A person was tested randomly. What is the probability that he/she has contracted the disease?}
(ii) Given that the person has not contracted the disease, what is the probability that the person is from category \( A_2 \)?