An experimental composite engine block for an automobile will trim 20 pounds of weight compared with a traditional cast iron engine block. It is estimated that at least $2,500 in life-cycle cost will be saved for every pound of weight reduction over the engine's eight-year expected life. Given that the engine's life is eight years, what assumptions have been made to arrive at $2,500 per pound savings?

Fixed and Variable kind of question... Would like a different answer than the guided solution given