If you’ve found our other riddles and brain teasers too easy, try this collection of really hard riddles instead. These are some of the most difficult riddles and they are sure to challenge your brain and give it a good work out!
They may seem impossible but don’t worry – although they are challenging, all the riddles have answers that can be logically worked out. See how well you do with these super tough riddles!
16 Really Hard Riddles
You are lost in the woods and the path you are following forks into two: a path to the left and one to the right. One path will lead you to safety while the other will cause you to be lost forever.
At the fork are two twin sisters who know which path is which. The sisters are identical in every way except one: one of the sisters always tells the truth while the other always lies.
You can ask only one question and you don’t know which sister is which. What can you ask them so you know which path to take?
Ask one of the sisters which path their sister would tell you to take.
Let’s say the left hand path is the correct one to follow. The sister that lies knows their truthful sister would tell you the left hand path, so as they always lie they will tell you the right hand path.
The honest sister knows their lying sister will tell you the right hand path and because they’re honest, they will tell you this. So you should follow the opposite path to that which you are told, regardless of which sister tells you.
As a stone inside a tree, I’ll help your words outlive thee. But if you push me as I stand, the more I move the less I am.
What am I?
There are three chests, each of which contains 100 coins. One chest has 100 gold coins, one has 100 silver coins, and the third has an equal split of 50 gold coins and 50 silver coins.
Each chest is labelled, but all are labelled incorrectly. You are allowed to pick one coin from just one of the chests and after his you must correctly identify each of the three chests.
What should you do?
Take a coin from the chest labeled 50/50.
If you pick a gold coin, you know that chest must contain all gold coins (it can’t be the 50/50 chest because all the chests are incorrectly labelled). So the chest labelled silver must be the 50/50 chest and the one labelled gold must be the silver chest.
On the other hand if you pick a silver coin, you know that chest must contain all silver coins, the one labelled silver must be the gold chest and the one labelled gold must be the 50/50 chest.
Where there is light is the only place I can live. Yet if light shines on me I die.
What am I?
There was a plane crash in which every single person was killed. Yet there were 12 survivors. How?
The 12 survivors were married, not single.
Turn me on my side and I am everything. Cut me in half and I am nothing.
What am I?
The number 8. On its side, it looks like the symbol for infinity and when you cut it in half, it looks like two zeroes.
You have two ropes, each of which takes exactly one hour to burn if lit from one end. The ropes are not identical, nor are they uniform, i.e. it doesn’t necessarily take half an hour for half the rope to burn.
With only these two ropes and a way to light them, how do you measure out 45 minutes?
You can do this in the following way:
First, light both ends of one rope and only one end of the other rope.
This will cause the first rope to burn out in 30 minutes (as you lit both ends it will burn in half the time as if you’d only lit one end).
When the first rope burns out, there will be 30 minutes left on the second rope (as each rope takes one hour to burn when lit from one end).
So then, light the other end of the second rope so both ends of it are now burning. This rope will now burn out in another 15 minutes.
The total time elapsed at this point will be 45 minutes (30 + 15 = 45 minutes).
I have cities but no houses, forests but no trees, water but no fish.
What am I?
You want to boil an egg for exactly 15 minutes but you only own a 7-minute hourglass and an 11-minute hourglass.
How can you achieve what you want?
Turn both hourglasses over as you start boiling the egg.
After 7 minutes the 7-minute hourglass will run out. Turn it over to start again.
In another 4 minutes the 11-minute hourglass will run out.
At this point, turn over the 7-minute hourglass. It will now take another 4 minutes to run out.
When it does so, your egg will have been boiling for exactly 15 minutes (7 minutes + 4 minutes + 4 minutes).
What jumps when it walks and sits when it stands?
It’s late at night and dark. A group of 4 friends, with just one torch between them, come to a river.
The only way across this river is a rickety old bridge that will only hold 2 people at a time and anyone crossing the bridge needs the torch to safely cross.
Alison is able to cross the bridge in 1 minute, Brian takes 2 minutes, Carol takes 5 minutes, and it takes Dave 8 minutes to cross the bridge.
Whenever 2 people cross the bridge together, they can only move at the pace of the slower person. Everyone must get across the bridge in 15 minutes.
How can they achieve this?
Alison and Brian cross the bridge together. This takes 2 minutes.
Alison then returns with the torch which takes 1 minute.
Carol and Dave then cross the bridge together which takes 8 minutes.
Brian then returns with the torch. This takes another 2 minutes.
Finally, Alison and Brian cross the bridge again, taking another 2 minutes for a total time of 15 minutes.
If you eat me, my sender will eat you.
What am I?
A fish hook
A man runs away from home. He turns left, and keeps running.
After some time he turns left again and keeps running. He later turns left once more and runs back home.
Who was the man in the mask?
The catcher (in a baseball game).
There were 3 prisoners in the King’s dungeon. Two of them had perfect vision but the third prisoner was completely blind.
One day the King gathered the prisoners together and said to them, “I have 5 hats. 2 of the hats are black and 3 are white. I will blindfold each of you and then put one of the hats on each of your heads. I will then put the remaining two hats in another room. Next, I will remove your blindfolds. At this point you may look at your fellow prisoners but may not speak to them. The person that can tell me the color of the hat on his head will go free. Do not insult me by guessing, however, for if you guess and are wrong, you shall be executed.”
The hats were then placed on the prisoners’ heads and the blindfolds were removed.
The King then spoke to the first prisoner, a fully sighted man. “What is the color of the hat on your head” The prisoner looked around carefully but finally, not wanting to risk death by guessing, said that he did not know.
The King then spoke to the second prisoner, the other fully sighted man. “What is the color of the hat on your head” This prisoner also looked carefully at the hats upon the heads of the other two prisoners, but finally admitted that he also did not know.
At this point the King turned and began to walk away, assuming that the third prisoner who was blind could not know possibly the answer to the riddle.
But then the blind man spoke. “Excuse me, my lord,” he said, “but I am certain my hat is white.”
Surprised, the King turned around. He saw that the blind man was correct and ordered him to be freed at once.
How did the blind prisoner know the color of his hat?
If the first prisoner had seen two black hats on the other two prisoners, he would have known that he was wearing a white hat as there were only two black hats to begin with. As he didn’t know what color hat he had, this means the other two prisoners must either have been both wearing white hats or one wearing a white hat and the other a black one.
The second prisoner would know this once the first prisoner is unable to say what color his hat is, i.e. the second prisoner now knows that either both he and the blind prisoner are wearing white hats or one of them is wearing white and the other black. So if the blind prisoner was wearing a black hat, the second prisoner would know that he must be wearing a white hat.
As the second prisoner couldn’t work out what color hat he was wearing, this told the blind prisoner that he must be wearing a white hat (if the blind prisoner was wearing a black hat, the second prisoner would have been able to deduce that he was wearing a white hat).
Forwards I am heavy, backwards I am not.
What am I?
A man is found murdered in his office. The suspects are Peter, Julie, Jason, Molly and Brian.
In the office is a calendar with the numbers 6,4,9,10,11 written in blood.
Who is the killer?
Jason is the killer. The numbers indicate months and the first letter of each month spells the name of the murderer, e.g. the 6th month is June and the first letter of June is J, the 4th month is April and the first letter of April is a, and so on.
Congratulations if you solved these really hard riddles; you must be a real brainbox and really good at brain games!
Whether you solved them all or not and you want some more tough riddles (or even some easier riddles), why not check out our other free riddles and brain teasers too, including these: