A young entrepreneur make money with all kinds of ingenious ideas. He sets up a cow milking show in the country (Iowa?) and profits from local tourists, and sets up a train set in D.C.? to the amazement of locals and tourists.
Stump the Bookseller
New format, same book stumper solving.
Not sure, but I wonder whether this could be one of Keith Robertson’s ‘Henry Reed’ books.
No Coins, Please by Gordon Korman.
It sounds like “No Coins, Please” by Gordon Korman
http://en.wikipedia.org/wiki/No_Coins,_Please