Ryan is self-employed. This year Ryan used his personal auto for several long business trips. Ryan paid $1,940 for gasoline on these trips. His depreciation on the car if he was using it fully for business purposes would be $4,200. During the year, he drove his car a total of 12,400 miles (a combination of business and personal travel). (Do not round intermediate calculations. Round your final answer to the nearest dollar amount.)

a. Ryan can provide written documentation of the business purpose for trips totaling 2,480 miles. What business expense amount can Ryan deduct (if any) for these trips?

b. Ryan estimates that he drove approximately 2,090 miles on business trips, but he can only provide written documentation of the business purpose for trips totaling 1,120 miles. What business expense amount can Ryan deduct (if any) for these trips?