}(l) Blood Group & Males & Females & Total mathbf(O) & mathbf(2 0) & mathbf(2 0) & mathbf(4 0) A & mathbf(1 7) & mathbf(1 8) & mathbf(3 5) B & mathbf(8) & mathbf(7) & mathbf(1 5) AB & mathbf(5) & mathbf(5) & mathbf(1 0) Total & mathbf(5 0) & mathbf(5 0) & mathbf(1 0 0) A) If a subject was selected randomly and found to be female what is the probability that she has a blood group O?. B) What is the probability male given blood type A?. 41

## Step 1: Understanding the Probability Concept<br />### To find the probability of an event, we use the formula: <br />\[ P(\text{Event}) = \frac{\text{Number of favorable outcomes}}{\text{Total number of possible outcomes}} \]<br /><br />## Step 2: Calculating Probability for Part A<br />### For part A, we need to find the probability that a randomly selected female has blood group O. The number of females with blood group O is 20, and the total number of females is 50. Thus, the probability is:<br />\[ P(\text{Female with Blood Group O}) = \frac{20}{50} = \frac{2}{5} \]<br /><br />## Step 3: Calculating Probability for Part B<br />### For part B, we need to find the probability that a person is male given they have blood type A. The number of males with blood type A is 17, and the total number of people with blood type A is 35. Thus, the probability is:<br />\[ P(\text{Male | Blood Type A}) = \frac{17}{35} \]