Susan works for a large marketing firm where she earns $120,000 per year. susan wants to quit her job and start her own marketing firm. she estimates that her total costs on direct business expenses will be $30,000. susan will quit her job and start her own marketing firm only if she can earn $25,000 in economic profit. what is the minimum total revenue susan must be able to earn for her to quit her job?

Wo firms, a and b, each currently dump 50 tons of chemicals into the local river. the government has decided to reduce the pollution and from now on will require a pollution permit for each ton of pollution dumped into the river. it costs firm a $100 for each ton of pollution that it eliminates before it reaches the river, and it costs firm b $50 for each ton of pollution that it eliminates before it reaches the river. the government gives each firm 20 pollution permits. government officials are not sure whether to allow the firms to buy or sell the pollution permits to each other. what is the total cost of reducing pollution if firms are not allowed to buy and sell pollution permits from each other? what is the total cost of reducing pollution if the firms are allowed to buy and sell permits from each other? a. $3,000; $1,500 b. $4,500; $3,500 c. $4,500; $4,000 d. $4,500; $2,500