In the following examples, find the opportunity cost. Your answer should be a rate, as in "1.5 widgets per year" or "7 apples per week." Answer all parts.

a. Doug works in a woodworking shop and has a choice between to activities: He can sand one rocking chair per hour or he can inspect two board per hour. What is the opportunity cost of sanding one rocking chair?

b. Sheila works the front desk in one of the buildings on campus. Every hour during her shift she has a choice between two activities: organizing 300 files per hour or deleting 600 emails per hour. What is the opportunity cost of organizing 300 files?

c. Griselda is a creative writer and has a choice between writing one more novel this year or five more short stories this year. What is the opportunity cost of writing just half a novel, in terms of short stories?