Some riddles about love include: "What makes grown men cry, but humanity would go extinct without it?" and "What causes a sudden increase in heart rate, a loss of memory and overall brain function, but is not a drug?" The answer to both is "love".
Online collections and bookstores are the best places to find challenging riddles. Good Riddles Now, Riddlers and Brain Den maintain online collections of riddles with answers. Most major bookstores, such as Barnes & Noble, have collections devoted to riddles, brainteas...
A few popular riddles for adults include, "Is an older $100 bill worth more than a newer one?" The answer is, "Yes. A $100 bill is worth more than a $1 bill." Another example is, "When is homework not homework?" The answer is, "When it's turned in to the teacher."
The following are riddles intended for kids: What gets wetter and wetter the more it dries? What goes up and down the stairs without moving? What has a face and two hands, but no arms or legs? The answers to these riddles are as follows: a towel, a rug and a clock.
Riddles for children should challenge their thinking without being too frustrating, such as the following: "What has a face and hands but no arms or legs?" The answer is a clock, which has a "face" with numbers and "hands" that indicate time.
Many riddles are based off of love and romance. A number of these explicitly end with the word "love," while others require more advanced word play.
While the answer to a riddle can simply be called an answer, the term "solution" is also applicable. Either term is usually acceptable, although the type of riddle helps delineate which word is best for the riddle in question.