The chart below describes the 1231 assets sold by the Annie Company (a sole proprietorship) this year. Compute the gain or loss from each asset disposition and determine the net 1231 gain treated as long-term capital gain for the year. Assume there is a 1231 lookback loss of $10,000.

Asset	Acquired	Sold	Cost	Depreciation	Sale Price
Copier	6/11/08	5/11/2015	$50,000	$46,500	$ 1,000
Office building	9/13/05	9/24/2015	100,000	24,000	150,000
Delivery Van (not listed property)	1/12/07	1/13/2015	22,000	21,000	30,000
Tooling Machine	8/11/09	7/27/2015	50,000	37,000	19,000

Explain the concepts of 1231, 1245 and 1250. What are these provisions and why were they created? What was Congress trying to achieve by enacting these code sections?