Problem 3: An electronics store buys a particular model of cell phones at $49 each and sells them for $129 each. The store's fixed costs are $575 per month for rent, $2100 per month for employee salaries, and $125 per month for miscellaneous costs. How many cell phones of this type must the store sell each month in order to make a profit of $1000? Variable: c = the number of cell phones of this type sold each month Revenue Function: R(c) = Cost Function: C(c) = Profit Function: P(c) = Summary: Independent variable, c Revenue, R(c) Cost, C(c) Profit, P(c)