Correct answer: \(\frac{3}{5}\)
Explanation:
The total number of balls in the bag is: \[ 4 \, \text{(black balls)} + 6 \, \text{(red balls)} = 10 \, \text{balls} \] The number of red balls is 6. Therefore, the probability of drawing a red ball is: \[ P(\text{red ball}) = \frac{\text{number of red balls}}{\text{total number of balls}} = \frac{6}{10} = \frac{3}{5} \]
Hence, the probability of drawing a red ball is \(\frac{3}{5}\).
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 \( A_2 \)?