WXY Inc. makes and sells desk lamps, charging $SP for each desk lamp. The tools used to make the desk lamps cost $2700 while the supplies cost $18 per desk lamp. To break even, the company sells 90 desk lamps.

a. What will be the total cost if the company sells 100 desk lamps?

b. What is the variable cost per unit?

c. What is the lowest price WXY Inc. could charge and still break even with selling 90 desk lamps?