Percent Bloopers

A delightful book by E. Barbeau opens with this example:

How to get drunk and rich at the same time

The column Money angles: where else to invest? by Andrew Tobias in the May 17, 1993, issue of Time offers this advice for improving your financial worth:

Buy staples in bulk when they're on sale ... Consider a family that buys one bottle of wine each week. With the 10% discount many stores offer on wine by the case, they would be saving 10% every twelve weeks - more than 40% a year, tax free and largely risk free.

One can in fact do better; increase your consumption to one case per month and save 120% over a year, thus qualifying for a 20% payback from the merchant. (Submitted by Larry Zeitel of Loras College in Dubuque, IA.)

References

  1. E. J. Barbeau, Mathematical Fallacies, Flaws, and Flimflam, MAA, 2000
  2. A. K. Dewdney, 200% of Nothing, John Wiley & Sons, Inc., 1993

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