Trade of goods and services across national boundaries, as well as the mobility of businesses and labor through immigration, is called:

Alarge tank is filled to capacity with 500 gallons of pure water. brine containing 2 pounds of salt per gallon is pumped into the tank at a rate of 5 gal/min. the well-mixed solution is pumped out at the same rate. find the number a(t) of pounds of salt in the tank at time t.

Carlton industries is considering a new project that they plan to price at $74.00 per unit. the variable costs are estimated at $39.22 per unit and total fixed costs are estimated at $12,085. the initial investment required is $8,000 and the project has an estimated life of 4 years. the firm requires a return of 8 percent. ignore the effect of taxes. what is the degree of operating leverage at the financial break-even level of output?

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