Logic Riddles

Question: There are four men: Abe, Butch, Cam, and Dan. There are four hats: two white and two black. They each get a hat: Abe gets black, Butch gets white, Cam gets black, and Dan gets white. They don't know what hat color they have. Abe goes into a room so that no one can see his hat. The others line up in front of the door in the order Butch, Cam, and Dan (Butch can't see the others hats, Cam can see Butch's, and Dan can see Cam and Butch's hats). Whoever can figure out their hat color first wins $1,000. If they are wrong they are out of the running.

Which man can figure out his hat color without a doubt?

Question: Three gods A, B, and C are called, in no particular order, True, False, and Random. True always speaks truly, False always speaks falsely, but whether Random speaks truly or falsely is a completely random matter. Your task is to determine the identities of A, B, and C by asking three yes-no questions; each question must be put to exactly one god. The gods understand English, but will answer all questions in their own language, in which the words for yes and no are da and ja, in some order. You do not know which word means which.

What three questions can you ask?

Question: Tom wants to send Sally an expensive ring through the mail because they live thousands of miles apart. The only problem is that everything sent through the mail is stolen unless there is a lock put on it. Both Tom and Sally have plenty of locks and keys but they don't have any of the same locks or keys.

How can Tom send Sally the ring without it getting stolen?

Question: You have a bag with 'N' strings in it. You randomly grab two ends and tie them together until there are no more loose ends.

In the end, what is the expected number of loops (strings tied to their own end)?

Question: A farmer has three fields. One of them has 3 bundles of hay, another has 4, and the last has 5. How many would he have in the first field if he combined all of them in that field?