Take the following quiz:
Each of these questions has an obvious answer that is wrong. However, if you take one minute to think about the questions--BEFORE YOU ANSWER--you will come to the correct, less obvious answer. Over the years, I have found that those who can answer these questions tend to do very well in my economics classes.
MORAL: before answering the question, spend a minute or two thinking about what the question is.
HT: Big Thinking