7. Purchasing with Price Breaks. Universal Technologies, Inc. has identified two qualified vendors with the capability to supply certain of its electronic components. For the coming year, Universal has estimated its volume requirements for these components and has obtained price-break schedules from each vendor. (These are summarized as "all-units" price discounts in the table at the bottom of p. 333.) Universal's engineers have also estimated each vendor's maximum capacity for producing these components, on the basis of available information about equipment in use and labor policies in effect. Finally, because of its limited history with vendor A, Universal has adopted a policy that permits no more than 60 percent of its total unit purchases on these components to come from vendor A. a. What is the minimum total cost for Universal's purchases? b. In the optimal solution to part (a). which purchases are made at discounted prices