Answer:
a) Therefore, the probability is P=1/52.
b) Therefore, the probability is P=9/400.
Step-by-step explanation:
We know that a batch of 40 parts contains six defects.
a) We calculate the probability that the both parts are defective, if two parts are drawn randomly one at a time without replacement.
The probability for the first is 6/40.
The probability for the second is 5/39.
Therefore, we get
[tex]P=\frac{6}{40}\cdot \frac{5}{39}\\\\P=\frac{1}{52}\\[/tex]
Therefore, the probability is P=1/52.
b) We calculate the probability that the both parts are defective, if two parts are drawn randomly one at a time with replacement.
The probability for the first is 6/40.
The probability for the second is 6/40.
Therefore, we get
[tex]P=\frac{6}{40}\cdot \frac{6}{40}\\\\P=\frac{9}{400}\\[/tex]
Therefore, the probability is P=9/400.
