David tunes pianos in his spare time for extra income. buyers of his service are willing to pay $135 per tuning. one particular week, david is willing to tune the first piano for $115, the second piano for $125, the third piano for $140, and the fourth piano for $175. assume david is rational in deciding how many pianos to tune. his producer surplus is :
a) $30 (answer but i don't get why)
b) $75
c)$20
d) $-15

Uppose that the federal reserve purchases a bond for $100,000 from donald truck, who deposits the proceeds in the manufacturer’s national bank. what will be the impact of this purchase on the supply of money? the money supply will increase by $100,000. the money supply will increase by $80,000. the money supply will increase by $500,000. this action will have no effect on the money supply. if the reserve requirement ratio is 20 percent, what is the maximum amount of additional loans that the manufacturer’s bank will be able to extend as the result of truck’s deposit? the maximum additional loans is $100,000. the maximum additional loans is $80,000. the maximum additional loans is $20,000. the maximum additional loans is $500,000. given the 20 percent reserve requirement, what is the maximum increase in the quantity of checkable deposits that could result throughout the entire banking system because of the fed’s action? this action will have no effect on the money supply. the money supply will eventually increase by $80,000. the money supply will eventually increase by $500,000. the money supply will eventually increase by $100,000.

Slimwood corporation made sales of $ 725 million during 2018. of this amount, slimwood collected cash for $ 670 million. the company's cost of goods sold was $ 300 million, and all other expenses for the year totaled $ 400 million. also during 2018, slimwood paid $ 420 million for its inventory and $ 285 million for everything else. beginning cash was $ 110 million. carter's top management is interviewing you for a job and they ask two questions: (a) how much was carter's net income for 2018? (b) how much was carter's cash balance at the end of 2016? you will get the job only if you answer both questions correctly.

Gdp has grown in a country at 3% per year for the last 20 years. the labor force has grown at 2% per year and the quantity of physical capital has grown at 4% per year. a 1% increase in average physical capital per worker (other things equal) raises productivity by 0.3%. average education has not changed. how much has growing physical capital per worker contributed to productivity growth in this country? choose the correct answer from the following choices, and then select the submit answer button. answer choices 0.3% 0.6% 3.0% 6.0%