Delta Shoe Ltd. manufactures only one type of shoe and has two divisions, the Sole Division and the Assembly Division. The Sole Division manufactures soles for the Assembly Division, which completes the shoe and sells it to retailers. The Sole Division "sells" soles to the Assembly Division. The market price for the Assembly Division to purchase a pair of soles is $20. (Ignore changes in inventory.) The per u are based on the production of 60,000 pairs of shoes. Assembly's costs per completed pair of shoes are: Assume the transfer price for a pair of soles is 180% of total costs of the Sole Division, and 40,000 of soles are produced and transferred to the Assembly Division. The Sole Division's operating income is