Mathematical puzzles

Puzzles, situation puzzles and recreational mathematics.

situation puzzles and recreational mathematics. Neuron juice

Neuron juice.

The important thing is not to stop questioning. (Albert Einstein.)

Math Puzzles

In this site you can find a selection of the most popular riddles and situation puzzles. Obviously, neither are here all who matter nor they matter all who are here. Some of them have been taken from the missing Snark list; others from books and other have been on my mind for a long time.


Every suggestion will be appreciated and included in this list.


Two of the riddles deserve special treatment, The riddle of the ages and the piano student is the one I always propose as a challenge. The other one is "Einstein's puzzle"  —if you don't know it yet, I highly recommend it.


Riddles and situation puzzles are mixed because of the difficulty of dividing them correctly into two independent groups, as some of them could be included in both groups.




Libro de Martín Gardner, los acertijos de Sam Loyd 


Martin Gardner was a great science writer famous for the publication of numerous books on recreational mathematics translated into many languages.


One such book , its cover attached to this riddle is " The riddles of Sam Loyd ".


Sam Loyd (Samuel Loyd ) was a chess player occupied the 15 place worldwide, author of ingenious chess problems and puzzles maker of recreational mathematics.


One of his most famous works is dedicated to Tangram , with 700 designs.


One of his mathematical puzzles is as follows: Is it legal the marriage of a man with his widow's sister ?



 -- Solving the riddle of Sam Loyd --






Acertijos con ecuaciones 



The head of a tribe has 20 kilos of maize to distribute to its 20 neighbors and decide to do as follows:


  • Each of the kids will give you 3 kilos of maize.
  • Each of the women will be given two kilos of maize.
  • Each of the men will give them half a kilo of corn.


Knowing that at least there is a child , a woman and a man How many children , women and men are there?


Are you able to solve the puzzle with an equation? Or do using logic and ingenuity to find the solution?


See the solution to the riddle






acertijo del deposito


The riddle of the water tank or the tank issue is one of the content in the book " The nine chapters on mathematical art " one of the oldest books math China, dating back to the period of Zhou Dynasty.

We have a water tank of 48 m3 capacity with two filling pipes and drain .
The first filler pipe open one would take 12 hours to fill the tank .
The second filler pipe open only take six hours to fill the tank.
With fully fueled and the two filling lines closed , the discharge pipe would take eight hours to remove all the water and leave the empty tank.

If we start from the empty tank and open the three pipes how long it would take to fill the tank?

See the solution to the riddle





Lewis Carrol , mathematician , photographer and writer , best known as the author of Alice in Wonderland and in its variant mathematical work and studies within the branch of recreational mathematics.
One of his best known puzzles is the " monkey puzzle "



Portada acertijo del mono de Lewis Carroll 


In a simple frictionless pulley hangs a monkey on one side and the other a weight that perfectly balances the monkey.
To be totally purist in solving the puzzle , it is considered that the rope has no weight or friction.
What if the monkey tries to climb the rope?





By Gabriel García Reyes Retana, México.


Riddle 28:


When I went to Antwerp, I met a man who came with seven women , each woman with seven sacks and each sack seven cats ...


men, women , bags and cats ... how many were going to Antwerp ?


-- Solving the riddle--



27.- If 5 cats hunt 5 mice in 5 minutes , how many cats hunt 100 mice in 100 minutes ?.


-- Solving the riddle --



By Martín Askenasi.


26.- Put a number from 1 to 8 in each cell of the grid below without touching in any way, or lateral or diagonal with its predecessor or successor.




-- Solving the riddle --



By Martín Askenasi.


25.- Same letters equal value. different letters , different value. Each letter is worth a number from 0 to 9. M has value = 1 , the rest is not known


  S E N D
+ M O R E
- - - - -


-- Solving the riddle --



24.- half of two plus two, they are three?


-- Solving the riddle --




23. We have a container with 10 liters of water and one with 10 liters of wine, three liters of water are poured into the carafe of wine and mixed , then returned to take three liters of the mixture into the jug of water.

What will be after the change, more water in the bottle of wine or more wine in the bottle of water?


-- Solving the riddle --