There are three industrial firms in happy valley.

firm initial pollution level cost of reducing pollution by 1 unit
(units) (dollars)
a 30 20
b 40 30
c 20 10
the government wants to reduce pollution to 60 units, so it gives each firm 20 tradable pollution permits.

because firm (a/b/c) has the highest cost of reducing pollution by 1 unit, it would like to (buy 20 permits from/sell 20 permits to) another firm. because firm (a/b/c) has the lowest cost of reducing pollution by 1 unit, it is willing to (buy 20 permits from/sell 20 permits to) the firm with the highest cost.

complete the second column of the following table by indicating who buys and sells permits in this case. complete the fourth column of the table with the number of permits each firm ends up with after trading with the others. next, subtract the number of permits from the initial pollution level to determine how many units of pollution reduction each firm has to complete, and enter these values into the fifth column of the table. next, determine the total cost of reducing the pollution levels you determined in the previous column, and enter that into the final column of the table. finally, add up the total pollution reduction costs for each firm and enter the total amount in the final cell of the total row in the following table.

Exercise 18-15 sheffield appliance center is an experienced home appliance dealer. sheffield appliance center also offers a number of services for the home appliances that it sells. assume that sheffield appliance center sells ovens on a standalone basis. sheffield appliance center also sells installation services and maintenance services for ovens. however, sheffield appliance center does not offer installation or maintenance services to customers who buy ovens from other vendors. pricing for ovens is as follows. oven only $790 oven with installation service 850 oven with maintenance services 970 oven with installation and maintenance services 990 in each instance in which maintenance services are provided, the maintenance service is separately priced within the arrangement at $180. additionally, the incremental amount charged by sheffield appliance center for installation approximates the amount charged by independent third parties. ovens are sold subject to a general right of return. if a customer purchases an oven with installation and/or maintenance services, in the event sheffield appliance center does not complete the service satisfactorily, the customer is only entitled to a refund of the portion of the fee that exceeds $790. assume that a customer purchases an oven with both installation and maintenance services for $990. (b) indicate the amount of revenue that should be allocated to the oven, the installation, and to the maintenance contract.

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.

After the price floor is instituted, the chairman of productions office buys up any barrels of gosum berries that the producers are not able to sell. with the price floor, the producers sell 300 barrels per month to consumers, but the producers, at this high price floor, produce 700 barrels per month. how much producer surplus is created with the price floor? show your calculations.