what formula do i use?

Troy Engines, Ltd, manufactures a varlety of engines for use in heavy equipment. An outside supplier has offered to sell one type of carburetor to Troy Engines, Ltd, for a cost of $35 per unit. To evaluate this offer. Troy Engines, Lid.. has gathered the following information relating to its own cost of producing the carburetor internally: One-third supervtsory salaries; two-thirds depreclation of speclal equlpment (no resale value). Required: 1. What would be the finandal advantage (disadvantage) of buying 20,000 corburetors from the outside supplier? 2. Should the outside supplier's offer be accepted? 3. Suppose that if the carburetors were purchased, Troy Engines, Lid.. could use the freed capacity to launch a new product. The segment margin of the new product would be $200,000 per year. Given this new assumption, what would be the financial advantage (disadvantage) of buying 20,000 carburetors from the outside supplier? 4. Given the new assumption in requlrement 3, should the outside supplier's offer be accepted