Charles has decided to open a lawn-mowing company. To do so, he purchases mowing equipment for

$6,000, buys gasoline($2.10 in gas is required to mow each yard), and pays a helper $20.00 per yard. Prior to opening the lawn company, Charles earned $5,000 as a lifeguard at the neighborhood swimming pool. Assume the money he used to purchase the mowing equipment could otherwise have earned

5 percent per year in the bank and that the mowing equipment depreciates at 20 percent per year. Charles plans to mow 300yards per year. Charles's implicit cost of production is $ per year?