This year, on January 22nd, 2012 the price of a first class stamp went up to 45 cents.  When I was a child the price of a first class stamp was 8 cents.

When I was in college the price had jumped to 18 cents.

In 1988, it was at 25 cents.  I remember thinking, “Wow, it can’t get much higher than that.”

In 2000, the price of a first class stamp was: 33 cents.

I had to go and buy 1 cent stamps because each time the stamps go up now, it is by 1 cent. The forever stamps are great, but I do like to get the tribute or limited edition stamps. They are more colorful.

Take a look at the 4 cent stamp pictured below.

4 cent stamp

So are you ready for my question?  Here we go…answer quickly..if you can.  How many 4 cent stamps in a dozen?

The above is an old postage stamp from 1962, when first class mail was only 4 cents.  Oh, by the way..if you said that there are three 4 cent stamps in a dozen.  You made a common mistake.  There are twelve stamps in a dozen.  It doesn’t matter how much they cost.  However, by stating how much they cost, I placed a red herring in a question.  I knew that you would factor that number into how you would solve the problem.  It is a common pitfall of what is called Heuristics.  Heuristics are short cuts that our mind uses to solve what appears to be common problems.

As you read the problem, your memory of old story problems from school is recalled.  You look at the numbers and quickly find that 3 times 4 equals 12.  Problem solved.  Except that that was not the correct data.  If I would have asked:  How many 5 cent stamps in a dozen.  You would have answered the question correctly because five does not go into 12 and you would have thought out the problem more carefully.  Oops!