Ecobrite labs performs tests on water samples supplied by outside companies to ensure that their wastewater meets environmental standards. customers deliver water samples to the lab and receive the lab reports via the internet. the ecobrite labs facility is built and staffed to handle the processing of 100,000 tests per year. the lab facility cost $160,000 to build and is expected to last 10 years and will have no salvage value. processing equipment cost $250,000 and has a life expectancy of five years and will have no salvage value. both facility and equipment are depreciated on a straight-line basis. ecobrite labs has six salaried laboratory technicians, each of whom is paid $30,000. in addition to the salaries, facility, and equipment, ecobrite labs expects to spend $50,000 for chemicals and other supplies (assuming 100,000 tests are performed). last year, 86,000 tests were performed. calculate the total cost of resources supplied, and break this into the cost of activity used and the cost of the unused activity.

Wallis company manufactures only one product and uses a standard cost system. the company uses a predetermined plantwide overhead rate that relies on direct labor-hours as the allocation base. all of the company's manufacturing overhead costs are fixed—it does not incur any variable manufacturing overhead costs. the predetermined overhead rate is based on a cost formula that estimated $2,886,000 of fixed manufacturing overhead for an estimated allocation base of 288,600 direct labor-hours. wallis does not maintain any beginning or ending work in process inventory.

Kiona co. set up a petty cash fund for payments of small amounts. the following transactions involving the petty cash fund occurred in may (the last month of the company's fiscal year). may 1 prepared a company check for $350 to establish the petty cash fund. 15 prepared a company check to replenish the fund for the following expenditures made since may 1. a. paid $109.20 for janitorial services. b. paid $89.15 for miscellaneous expenses. c. paid postage expenses of $60.90. d. paid $80.01 to the county gazette (the local newspaper) for an advertisement. e. counted $26.84 remaining in the petty cashbox. 16 prepared a company check for $200 to increase the fund to $550. 31 the petty cashier reports that $380.27 cash remains in the fund. a company check is drawn to replenish the fund for the following expenditures made since may 15. f. paid postage expenses of $59.10. g. reimbursed the office manager for business mileage, $47.05. h. paid $48.58 to deliver merchandise to a customer, terms fob destination. 31 the company decides that the may 16 increase in the fund was too large. it reduces the fund by $50, leaving a total of $500.

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.