A man has an apple orchard and sells to his first customer half of all the apples plus half an apple; to the second customer he sells half of rest of the rest plus half an apple; to the third, half of the remainder plus half an apple, and so on. To the seventh customer he sells half of what remains and another half apple. And that is all he had. How many apples did the farmer start out with? The solution can be downloaded as a PDF file.
Taken from Algebra can be fun by Y I Perelman, Mir Publishers.
Excel Solver add-in: Chandoo’s blog is an excellent place to know more about this add-in. Xlsx file used in this quiz can be downloaded here.