Answer:
1. 1/120
2. 7/24
Step-by-step explanation:
n = 10
Number of defective = 3
1. Probability of all defective =
(Number of defective/n) x (number of defective -1/n -1)...(number of defective -n/n-1)
=3/10 x 2/9 X 1/8
= 6/720
= 1/120
2. probability of none defective
Since 3 are defective, those that are not defective = 7
The probability is therefore:
7/10 x 6/9 x 5/8
= 210/720
= 7/24.