A computer manufacturer has four different series of laptops. Customers selecting one of these laptops have a choice of four microprocessor types, two memory capacities, and three screen sizes. How many different selections can a customer make? Question 9. A company bought an equipment at a cost of $115,000. The equipment is to be depreciated by the double declining-balance method over 10 years. What is the book value of the equipment at the end of the seventh year? Question 10. In a survey of 150 consumers conducted in a shopping mall, 75 consumers indicated that they buy Brand 4 of a certain product, 56 buy Brand B, and 38 buy both brands. How many consumers participating in the survey buy exactly one of these brands?