Riddle: A man is discovered dead sitting at his desk, alone in the locked office. He did not commit suicide and there was no weapons in the room. The only clue is a sealed envelope on the desk in front of him. How did he die?
Answer: The envelope glue was poisoned and when the man licked the envelope to seal it, he died.
Riddle: At a children's party, 10 kids had juice, 8 kids had cake, and 6 kids had juice and cake. How many kids were there at the party?
Answer: Tweleve kids. Six kids had juice and cake, leaving two out of the cake eaters that didn't have juice. As there were ten juicers, there must be twelve kids in total.
Riddle: A bottle costs a dollar more than a cork. Together they cost 110 cents. How much does the bottle cost and how much does the cork cost?
Answer: The right answer is that the bottle costs 105 cents, and the cork costs 5 cents.
Riddle: A bird has a head 9cm long. The tail is equal to the size of the head plus a half of the size of the body. The body is the size of the head plus the tail. How long is the bird?
Answer: 72cm. Th head is 9cm. The tail is 18 + 9= 27cm. The body is 9 + 18 + 9= 36cm. 9 + 27 + 36= 72cm.
Riddle: The distance from the Earth to the Sun is about 100 million miles. The speed of light is 186,000 miles per second, and light takes eight minutes to reach the Earth from the Sun. Let's say the Sun rose at 6am this morning, and that by some freak of physics the speed of light is suddenly doubled to 372,000 miles a second. What time will the Sun rise tomorrow?
Answer: 6am again. After all, what diffrence does the speed of light make to the answer?  It's irrelevant- only the speed of the roation of the Earth matters here.  
Riddle: If 6 doubloons are worth 1 1/2 ducats, how many ducats are 27 doubloons worth?
Answer: 6 3/4 ducats (27/6=4 1/2. 4 1/2 x 1 1/2= 6 3/4)
Riddle: A great banquet was prepared for a Roman emperor and his courtiers. 22 Dormice, 40 Larks' Tongues, 30 Flamingos and 40 Roast Parrots were served. How many portions of Boiled Ostrich were served?
Answer: 42. Each vowel is worth 2 and each consonant 4, so Dormice gives 22, ect.
Riddle: What is the next number in the series? 7,645 5,764 4,576...
Answer: 6,457. The last digit is moved to the front to make the next number.
Riddle: If it takes four rat catchers four minutes to kill fourrats, how many rat catchers would be needed to catch 50 rats in 50 minutes?
Answer: The same number of rat catchers- Four.
Riddle: What grows down as it grows up?
Answer: A goose.