Fixing up old houses requires plumbing and carpentry. Jack $($who is a jack of all trades but is a master of none$)$ is a decent carpenter and a decent plumber, but is not particularly good at either. He can fix up threehouses in a year if he does all of the carpentry and plumbing himself. His wage is $$60,000$per year.

Part $2$

Jack's average total cost of fixing up threeold houses is $

$20\mathrm{.}00020\mathrm{.}000.($Roundyour response to the nearest dollar.$)$

Part $3$

George is an excellent plumber and Harriet is an excellent carpenter. George can do all of the plumbing and Harriet can do all of the carpentry to fix up eighthouses per year. Each earns a wage of $$60,000$per year.

Part $4$

If George and Harriet work together and fix up eightold houses each year, their average cost is $

enter your response here.$($Roundyour response to the nearest dollar.$)$

Part $5$

This problem tells us that one of the sources of economies of scale is