When a die is thrown once, there are 6 possible outcomes, as the die has 6 faces numbered from 1 to 6. When the die is thrown twice, the total number of possible sample events can be found by multiplying the outcomes of the first throw by the outcomes of the second throw. Thus, the number of sample events is: \[ 6 \times 6 = 36 \] Therefore, the number of sample events when a die is thrown twice is 36.
The correct option is (D): \(36\)
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 \( A_2 \)?