Problem 121 of 7
Use conditional probability in a without-replacement context: select two defective parts from 6 defective and 14 good without replacement.
Using a hint is okay. It just tells the trainer to give you a little more review.
Hidden until you reveal it.
update sample space after first event.
Hidden until you reveal it.
Update the sample space after the first event because there is no replacement.
Enter your answer
Your answer is equivalent to the expected form.
Walkthrough
Full solution stays hidden until you ask for it.
1. Find the probability of the first event.
2. Update counts after the first event occurs.
3. Multiply by the conditional probability of the second event.
Use the worked steps, then substitute the final answer back into the original relationship to confirm it satisfies the prompt.
Using the original denominator for every draw when there is no replacement.