E12-29 (similar to)p. 483
The city of Seattle signed a lease for a photocopy machine at $3,200 per month and $0.02 per copy. Operating costs for toner, paper, operator salary, and so on are all variable at $0.03 per copy. Departments had projected a need for 105,000 copies a month. The city planning department predicted its usage at 34,000 copies a month. It made 41,000 copies in August. 更多
