Created by Jim Propp, this is a logic classic, IMHO.

1. The first question whose answer is B is question
A) 1 B) 2 C) 3 D) 4 E) 5
2. The only two consecutive questions with identical answers are questions
A) 6 and 7 B) 7 and 8 C) 8 and 9 D) 9 and 10 E) 10 and 11
3. The number of questions with the answer E is
A) 0 B) 1 C) 2 D) 3 E) 4
4. The number of quesions with the answer A is
A) 4 B) 5 C) 6 D) 7 E) 8
5. The answer to this question is the same as the answer to question
A) 1 B) 2 C) 3 D) 4 E) 5
6. The answer to question 17 is
A) C B) D C) E D) none of the above E) all of the above
7. Alphabetically, the answer to this question and the answer to the following question are
A) 4 apart B) 3 apart C) 2 apart D) 1 apart E) the same
8. The number of questions whose answers are vowels is
A) 4 B) 5 C) 6 D) 7 E) 8
9. The next question with the same answer as this one is question
A) 10 B) 11 C) 12 D) 13 E) 14
10. The answer to question 16 is
A) D B) A C) E D) B E) C
11. The number of questions preceeding this one with the answer B is
A) 0 B) 1 C) 2 D) 3 E) 4
12. The number of questions whose answer is a consonant is
A) an even number B) an odd number C) a perfect square D) a prime E) divisible by 5
13. The only odd-numbered problem with answer A is
A) 9 B) 11 C) 13 D) 15 E) 17
14. The number of questions with answer D is
A) 6 B) 7 C) 8 D) 9 E) 10
15. The answer to question 12 is
A) A B) B C) C D) D E) E
16. The answer to question 10 is
A) D B) C C) B D) A E) E
17. The answer to question 6 is
A) C B) D C) E D) none of the above E) all of the above
18. The number of questions with answer A equals the number of questions with answer
A) B B) C C) D D) E E) none of the above
19. The answer to this question is
A) A B) B C) C D) D E) E
20. Standardized test is to intelligence as barometer is to
A) temperature B) wind-velocity C) latitude D) longitude E) all of the above