This is the answer to Planet X Fingers. Don't read on unless you want to know.

Answer:

• 7 fingers per hand; A total of 28 fingers. The discounts are 98, 98 and 272; (1-98/784) * (1-98/784) * (1-272/784) = .5

There is also a 40 finger solution (320, 320, 350) but it isn't the lowest, as required in the puzzle.