Norfisk Oil is drilling some exploratory wells on the mainland of Norway. The results are described as either a ‘dry well' or a ‘producer well'. Past experience suggests that 10% of exploratory wells are producer wells. If the company drills 12 wells, what is the probability that all 12 are producer wells? What is the probability that all 12 are dry wells? What is the probability distribution for the number of dry wells?