Before Mount Everest
Before Mount Everest was discovered, which was the highest mountain in the world?
SOLUTION
It was still Mount Everest (even though not yet discovered).
Category: Brain Teasers
A collection of Math, Chess, Detective, Lateral, Insight, Science, Practical, and Deduction puzzles, carefully curated by Puzzle Prime.
We do not know where this puzzle originated from. If you have any information, please let us know via email.
Haystacks
You have 10 fields and keep 1 haystack in the first one, 2 haystacks in the second one, 3 haystacks in the third one and so on. How many haystacks will you have if you combine all of them in your first field?
SOLUTION
You will have one big haystack.
Tough Decisions
You are driving your car along the road in a very harsh snowy weather and reach a bus stop. On this bus stop you see that there are three people waiting – your best friend, a sick old lady and the girl of your dreams. The car unfortunately can accommodate only 2 people (including you), so you can not take all of them with you. What will be your choice?
SOLUTION
The best solution is to let your friend drive the old lady and you stay with the girl of your dreams on the bus stop.
Potatoes and Wire
If you have two spheres, you can always make a loop with some wire, such that it fits both of them (for example you can shape it as a circle). If you have any two potatoes, can you do the same?
SOLUTION
Yes, you can. Just take the two potato surfaces and intersect them. Their intersection will give you the shape of a wire which fits them both.
Man in the Elevator
One man who lives on the 12th floor every day takes the elevator to go to work. When he comes back in the evening, unless it is raining or there are other people in the elevator, he goes with it just to the 8th floor and then uses the stairs for the last 4 floors. Why does he do this?
SOLUTION
The man is very short. Unless he has an umbrella or can ask other people to press the button for him, he can’t make the elevator go to the 12th floor.
Escaping the Tower
A Queen is captured in the top room of a very high tower, along with her son and daughter. Outside their window, there is a pulley with a rope
SOLUTION
1. The stone is sent down in a basket.
2. The
3. The daughter goes down, the son goes up.
4. The stone is thrown back down.
5. The queen goes down, the daughter and the stone go up.
6. The stone goes down.
7. The
8. The daughter goes down, the son goes up.
9. The stone is thrown back down.
10. The son goes down, the stone goes up.
FEATURED
Domino and Chess
Can you cover the chess board with 31 domino pieces, such that only two opposite corners are left uncovered?
SOLUTION
The answer is NO. Every domino piece covers exactly one black and one white square on the chess board. Since initially you start with a different number of available white and black squares on the chess board, it is impossible to cover it with domino pieces.
Touching Pencils
Can you arrange 6 new identical pencils in space such that every two of them touch each other? What if you have 7 pencils?
Remark: The construction doesn’t need to be stable.
SOLUTION
Below you can see solutions for 6 and 7 pencils. The construction with 6 pencils is stable, the construction with 7 pencils – not.
Fly Escape
Move only 2 matchsticks, so that the fly will escape from the trap. The shape of the trap must remain the same.
SOLUTION
The solution is shown below.
Chessboard Madness
You have unlimited number of knights, bishops, rooks and kings. What is the biggest number of pieces (any combination) you can place on a chessboard, so that no piece is attacked by another one?
SOLUTION
If we put 32 knights on all black squares, then no two pieces will attack each other. Now let’s see that if we have more than 32 pieces, then there will be two which attack each other. Split the chessboard in 8 rectangular sectors of size 2×4. It is not hard to see that if we have more than 4 pieces in the same 2×4 sector, then 2 of them will attack each other. Therefore we can place at most 4 × 8 = 32 pieces on the chessboard.