A small company that shovels sidewalks and driveways has 100 homes signed up for its services this winter. It can use various combinations of capital and labor: lots of labor with hand shovels, less labor with snow blowers, and still less labor with a pickup truck that has a snowplow on front. To summarize, the method choices are:

• Method 1: 50 units of labor, 10 units of capital
• Method 2: 20 units of labor, 40 units of capital
• Method 3: 10 units of labor, 70 units of capital

If hiring labor for the winter costs $100/unit and a unit of capital costs $400, what production method should be chosen? What method should be chosen if the cost of labor rises to $200/unit?