The 18 cent piece
Subscribe to Decision Science News by Email (one email per week, easy unsubscribe)
WHAT SET OF COINS MINIMIZES THE AVERAGE NUMBER OF COINS NEEDED TO MAKE CHANGE?
We draw your attention to the cleverly-titled article What This Country Needs is an 18 Cent Piece. It’s a piece of recreational mathematics that asks the question “what set of coins minimizes the average number of coins needed to make change”?
It’s fun, but I’m sure my marketing colleagues will bristle at the assumption “we assume that every amount of change between 0 and 99 is equally likely.” That said, the author does acknowledge nines pricing and Benford’s law in a footnote.
We also imagine this to be the kind of article that when dangled before our serial co-author Preston McAfee, would cause him to engage in a few hours of recreational mathematics himself.
CITATION
Shallit, J. The Mathematical Intelligencer (2003) 25: 20. https://doi.org/10.1007/BF02984830
