This plugin by Fubra is designed to allow wordpress blog owners to create their own quizzes and surveys.
Editable options for quizes and surveys are
Take users contact details
Completion notification (Instant, Batched – hourly or daily or not at all)
Editable options for quiz sections are
Type – Multiple choice or Text input.
Difficulty – Easy, medium, hard or mixed which is even number of each difficulty unless the number is odd then the remainder from dividing by 3 is added to one difficulty randomly.
Number of Questions
Requires WordPress Version: 2.9.2 or higher Compatible up to: 3.1
Download and info: http://wordpress.org/extend/plugins/wp-survey-and-quiz-tool/