Please help and show on Graph.

You are advising a friend who sells paintings on the sidewalk. What price should she put on all the paintings given the following information:

Price $100 Quantity demanded 1

Price $80 Quantity demanded 2

Price $60 Quantity demanded 3

Price $40 Quantity demanded 4

And the fixed cost for her business is $50, while it costs her $40 to paint each additional painting, how many paintings should she sell if she sells each painting for the same price and what will that price be? Please show your work.