Prepare the problem below using more than 1 variable. The copying service acquires machine operating costs of: $0.10 for copies 1 to 4, 0.05 for copies 5 to 8, 0.025 for copies nine and over, and has the capacity of 1000 copies per hour. 1 hour has been reserved for copying the 10-page article to be sold to MBA students. Suppose that all copies can be sold for $0.50 per article, find number of copies of article must be made?