In a crowd of 2000 computers on a network, 12 are faulty. We choose by repositioning 10 of them.
1. What is the probability of finding at least 2 defectives?
2. What is the mean value and the dispersion of the number X of defectives among them
where did we choose?
3. If we select until we find the first defective one and Y the number of required ones
of replicates, what is the distribution, mean, and variance of Y?