A sales division in a large IT consulting company prepares proposals and bids on engagements with companies who are considering purchasing new information systems. There is some randomness at work in this process, with varying numbers of competitors in each case and other factors affecting the customers' decisions. Generally they win 20% of the contracts that they bid on. If you were to build a model of the division's activity and wanted to include a random variable for winning contracts, what type of distribution would you use?