Not so good at math
I’m a sucker for tricky math problems, and for nifty illustrations of human psychology (what other kind is there?)
Seth Godin posed a good one last week:
Not so good at math
A simple quiz for smart marketers:
Let’s say your goal is to reduce gasoline consumption.
And let’s say there are only two kinds of cars in the world. Half of them are Suburbans that get 10 miles to the gallon and half are Priuses that get 50.
If we assume that all the cars drive the same number of miles, which would be a better investment:
- Get new tires for all the Suburbans and increase their mileage a bit to 13 miles per gallon.
- Replace all the Priuses and rewire them to get 100 miles per gallon (doubling their average!)
Trick question aside, the answer is the first one. (In fact, it’s more than twice as good a move).
We’re not wired for arithmetic. It confuses us, stresses us out and more often than not, is used to deceive. [PS here are some reader-contributed explanations for those still lost: Charlie, and Nariman.]
The trick to understanding this problem is to focus on the gallons, not the miles. Change Miles-per-Gallon to Gallons-per-Mile and normalize for miles driven.
As a political snipe, which program would our Politicians be most likely to sell? Most able to sell?
This is tricky! It sure seems like such a big improvement in the Prius’s mpg would be better than a small improvement in the SUV’s mpg. But if you do the math, you see that that is not the case.
Comment by Kathy — 3. September 2009 @ 12:42