At a certain supplier, a machine of type A costs $20,000 and a machine of type B costs $50,000. Each machine can be purchased by making a 20 percent down payment and repaying the remainder of the cost and the finance charges over a period of time. If the finance charges= 40 percent of the remainder of the cost, how much less would 2 machines of type A cost than 1 machine of type B?

A. $10,000
B. $11,200
C. $12,000
D. $12,800
E. $13,200

Answer: E

Source: GMAT Prep