I am struggling how the prof got to the following answer of $19.39. Can you please provide step by step help?

Lee Inc. just purchased a digital color printer for $240,000 to launch its publishing project.This printer will be fully depreciated by the straight-line method over its 3year economic life, and can be sold for $48,000 at the termination of the project.The variable costs are $15 per copy, and annual fixed costs are $120,000.An annual sales volume of 50,000 copies of the book is expected over the life of this 3-year project.The marginal tax rate is 30% and the appropriate discount rate is 14%. compute the selling price of each copy of the book that results in a zero NPV for this publishing project.