trig word problem, need help : )?

Question

hey guys, i need help with a problem for my trig class. if any of you could answer that would be great, i just don't know how to set up the problem

A store owner bought n dozen toys at a cost of $3.00 per dozen, and sold them at $.75 apiece. Express the profit as a function of n.

Answer 1

Cost: 3.00n
Gross: .75(12n) = 9n
Profit = Gross - Cost
P = 9n - 3n
P = 6n