Hello, zorro!

Out of every 100 jobs received at a computing center:

50 are of class 1, 30 of class 2 and 20 of class 3.

i) A sample of 30 jobs is taken without replacement.

Find the probability that the sample will contain 10 jobs of each class.

Answer: .

ii) A sample of 30 jobs is taken with replacement.

Find the probability that there will be exactly 12 jobs of class 2

Answer: .