Correct answer: \(\phi\)
Explanation:
Two events \( E_1 \) and \( E_2 \) are said to be mutually exclusive if they cannot occur at the same time. This means that the intersection of \( E_1 \) and \( E_2 \), denoted by \( E_1 \cap E_2 \), is the empty set, i.e., \( E_1 \cap E_2 = \emptyset \). Therefore, the value of \( E_1 \cap E_2 \) is \( \phi \), which represents the empty set.
Hence, \( E_1 \cap E_2 = \phi \).
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 \( A_2 \)?