10 Complex Riddles with Answers

These complex riddles are famous for their clever twists and challenges to traditional thinking. They have been told for generations and continue to be popular and provide great opportunities for critical thinking and problem-solving.

Take a moment to read each riddle and let your imagination wander. When you’re ready, reveal the answer. Remember, there’s no rush – give yourself time to think and enjoy the challenge.

If you answered correctly, congratulations! If not, don’t be too hard on yourself. After all, these are complex riddles.

Remember, as you practice, your critical thinking skills will improve over time, and you’ll likely get it right the next time. Keep at it!

If you have kids at home you check our easy riddles for kindergarten. For one-line short riddles with answers go HERE

The Riddle of the Sphinx

What creature walks on four legs in the morning, two legs at noon, and three in the evening?


The Riddle of the Sphinx is a famous riddle from Greek mythology and is known for its metaphorical use of the stages of a human’s life.

Here’s the explanation:

Morning: This represents the early stage of life, i.e., infancy and childhood. During this time, humans crawl on all fours (hands and knees), which is akin to walking on “four legs.”

Noon: This symbolizes the middle stage of life, which is adulthood. During this stage, humans typically walk on two legs, representing the full upright stance of an adult.

Evening: This denotes the later stage of life, old age. In this stage, many people use a cane to aid in walking, effectively using “three legs” (two legs plus a cane).

The riddle uses the metaphor of a day (morning, noon, evening) to represent the different phases of a human’s life. It’s a clever way of illustrating the human life cycle and the changes in physical capabilities as one ages. The Sphinx used this riddle to test the wisdom of those who encountered it, according to the myth.

The River Crossing Riddle

You have a river, and you need to get a wolf, a goat, and a cabbage across it in a boat, but you can only take one of them at a time.

If you leave the wolf with the goat, it will eat the goat, and if you leave the goat with the cabbage, it will eat the cabbage. How do you get them all across safely?” –


Take the goat across first, then come back alone for the wolf, take the wolf across, but bring the goat back with you. Leave the goat on the original side and take the cabbage across. Finally, come back alone and bring the goat across.

The Monty Hall Problem

You’re a contestant on a game show. There are three doors, behind one of which is a car, and behind the other two are goats. You pick one door, and then the host, who knows what’s behind all the doors, opens another door revealing a goat. Now, you have the option to stick with your original choice or switch to the other unopened door. What should you do to maximize your chances of winning the car?


You should switch doors to maximize your chances of winning.

The Two Doors Riddle

You are standing in front of two doors. One door leads to certain death, and the other door leads to freedom. There are two guards, one in front of each door.

One guard always tells the truth, and the other always lies. You don’t know which guard is which, and you don’t know which door leads to freedom. You can ask one guard one question. What question should you ask to find the door to freedom?


Ask either guard, “If I were to ask the other guard which door leads to freedom, what would he say?” Then, choose the opposite of the guard’s answer.

The 100 Prisoners and a Light Bulb Riddle

There are 100 prisoners in separate cells, and there is a single light bulb in a room that is initially off. The prisoners are allowed to visit the room with the light bulb, but they cannot communicate with each other. Each prisoner can either turn the bulb on or leave it off.

They are also allowed to rearrange the bulb’s state however they wish. Once a prisoner is finished, they will not return to the room. The prisoners need to collectively determine when all of them have visited the room at least once. How can they do it?


Initially, one prisoner is assigned to always turn the light bulb on when they visit, and the others leave it off. When a prisoner enters the room and sees the light on, they know they are the first to enter since the last prisoner turned it on. After turning it off, they change their strategy to turning it off when they visit. This way, they can keep track of when all prisoners have visited the room.

The Three Jugs Problem

You have three jugs of 5 liters, 3 liters, and 2 liters. How can you measure exactly 4 liters?


Fill the 5-liter jug and use it to fill the 3-liter jug, leaving 2 liters in the 5-liter jug. Empty the 3-liter jug and pour the 2 liters from the 5-liter jug into it. Refill the 5-liter jug and use it to fill the 3-liter jug, which already contains 2 liters. This leaves exactly 4 liters in the 5-liter jug.

The Fox, Chicken, and Grain Puzzle

How do you transport a fox, a chicken, and a sack of grain across a river in a boat that only holds you and one of the three items, without leaving the fox alone with the chicken or the chicken alone with the grain?


First, take the chicken across the river and leave it on the other side. Go back and take the fox across. However, bring the chicken back with you. Leave the chicken on the original side and take the grain across the river. Finally, return to pick up the chicken and take it across.

The Four People Bridge Crossing Puzzle

Four people need to cross a bridge in 17 minutes. They walk at different speeds (1, 2, 5, and 10 minutes). Only two can cross at a time with one flashlight. How do you get all four across in the shortest total time?


First, the two fastest (1 and 2 minutes) cross together (2 minutes elapsed). The fastest (1 minute) goes back (3 minutes). The two slowest (5 and 10 minutes) cross (13 minutes). The second fastest (2 minutes) returns (15 minutes). Finally, the two fastest (1 and 2 minutes) cross again (17 minutes in total).

A Mother Dad Five Sons Riddle

A mother has five sons: January, February, March, April, and what is the name of the fifth son

A mother has five sons: January, February, March, April, and What is the name of the fifth son?


The answer to this riddle is in the question itself. The riddle cleverly leads you to think of months, but the actual name of the fifth son is stated in the riddle: “What”. So, the name of the fifth son is “What”.

This riddle is a classic example of a play on words, where the structure of the question misleads you to think about a different answer than the obvious one presented in the question.

I am a king, and my son is a king Riddle

I am a king who has no power to rule. My son is also a king but he too has no power. What are we?


The answer to this riddle is “A chessboard.” In the game of chess, both the player’s pieces include a king, and thus, on a single chessboard, there are two kings, symbolically representing the riddle’s statement. This riddle cleverly uses the context of a popular game to create a playful challenge.

3 Men Are Illiterate Riddle

Three men went for a swim in a pond, but when they came out, they found their clothes had been stolen. The men were illiterate and couldn’t read the signs in front of them. One sign said, “Clothes stolen if left unattended.” The second sign said, “The thief is among you.” What is the identity of the thief?


The thief is the one who didn’t look at the signs. Since all three men were illiterate and couldn’t read, only the thief would know to avoid looking at the signs that could incriminate him.

The Einstein’s Riddle

There are five houses, each of a different color and inhabited by men of different nationalities. These five homeowners each drink a different kind of beverage, smoke a different brand of cigar and keep a different pet. The question is: Who owns the fish?

These are the clues:

The Brit lives in the red house.
The Swede keeps dogs as pets.
The Dane drinks tea.
The green house is on the left of the white house.
The green house’s owner drinks coffee.
The person who smokes Pall Mall rears birds.
The owner of the yellow house smokes Dunhill.
The man living in the center house drinks milk.
The Norwegian lives in the first house.
The man who smokes Blends lives next to the one who keeps cats.
The man who keeps horses lives next to the man who smokes Dunhill.
The owner who smokes BlueMaster drinks beer.
The German smokes Prince.
The Norwegian lives next to the blue house.
The man who smokes Blends has a neighbor who drinks water.


The answer to Einstein’s Riddle (the Zebra Puzzle) is: The German owns the fish.

Here’s a brief explanation of how you arrive at the solution:

From the clues, you align the nationalities, house colors, beverages, cigar brands, and pets for each house. Using a process of elimination and logical deduction from the provided clues, you find that each detail corresponds to only one house.
For example, since the Norwegian lives in the first house and the first house is next to the blue house, and the middle house (third) has milk, you can start aligning other details.

You continue this process, considering where the green and white houses can be (since green is to the left of white), who drinks coffee, who smokes what, etc.

Eventually, you’ll find that only one house is left with an unspecified pet, and that house is occupied by the German. Since all other pets are accounted for, the German must have the fish.

The Light Bulb Three Switches Riddles

You are in a room with three switches, each of which corresponds to one of three light bulbs in another room. And, you cannot see the light bulbs from where the switches are. You can turn the switches on and off as much as you like, but once you open the door to check the bulbs, you can’t change the switches anymore. How can you determine which switch corresponds to which light bulb?

  • Turn on the first switch and leave it on for a few minutes.
  • Then, turn it off and quickly turn on the second switch.
  • Enter the room with the light bulbs.

The bulb that is lit corresponds to the second switch (the one you just turned on). The bulb that is off but warm corresponds to the first switch (the one you had turned on for a while and then turned off). The bulb that is off and cold corresponds to the third switch (the one you never turned on).

Last Thoughts

I hope you had a great time thinking about the answer to these complex riddles. If it is night time you might want to relax before going to bed by reading one of our night stories for adults.

You are doing great by looking brain teaser. It has proven to have so many benefits. But that’s a subject for another time. For now, I hope to see you soon.

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