Answer
She should charge 52 dollars for each lamp.
Work Step by Step
Let s represent the selling price. The basic relationship is: selling price equals cost plus profit.
Selling price = Cost + Profit
Selling price = s
Cost = 40
Profit = 30% $\times$ 40 = .3 $\times$ 40 = 12
Substitute these values into the equation to obtain:
s = 40 + 12
s = 52
She should charge 52 dollars for each lamp.
