Suppose 5% of the Flash-Disk manufactured by a company is faulty. If we take, 100 flash-Disk how many are expected to be faulty? It must be 5, right? If we take 100 flash-Disk, what is the probability that 5 of them are faulty? This is what bugging me. We know 5% are most likely to be faulty. So, in 100 flash-Disk 5 are most likely to be faulty. But how much likely?