The correct answer is (b), the third letter. Tversky and Kahneman XXXXXXXXXXfound that most people thought that the answer was (a), the first letter. Why do people make this mistake? Because, say...

The correct answer is (b), the third letter. Tversky and Kahneman (1974) found that most people thought that the answer was (a), the first letter. Why do people make this mistake? Because, say Tversky and Kahneman, they find it easier to think of examples of words that begin with r. By using the availability heuristic, they assume that the ease with which they can bring examples to mind means that such words are more common.