Engineering Economy 16th Edition by William Sullivan ,Elin Wicks, Koelling,

Exercise 3

A group of enterprising engineering students has developed a process for extracting combustible methane gas from cow manure (don't worry, the exhaust is odorless).With a specially adapted internal combustion engine, the students claim that an automobile can be propelled 15 miles per day from the "cow gas" produced by a single cow. Their experimental car can travel 60 miles per day for an estimated cost of $5 (this is the allocated cost of the methane process equipment-the cow manure is essentially free).
a. How many cows would it take to fuel 1,000,000miles of annual driving by a fleet of cars What is the annual cost
b. How does your answer to Part (a) compare to a gasoline-fueled car averaging 30 miles per gallon when the cost of gasoline is $3.00 per gallon