Welcome to MindCipher, a social repository of the world's greatest brain teasers, logic puzzles and mental challenges.
2 3 Tick Tock
With a seven-minute hourglass and an eleven-minute hourglass, what is the quickest way to time the boiling of an egg for fifteen minutes?
Submitted by Aakash
Easy
2.6
2 2 The Number Problem
What does 3685=? 8809=6 7111=0 2172=0 6666=4 1111=0 3213=0 7662=2 8096=5 9312=1 4444=0 6824=3 9999=4 0345=1 2359=1 5522=0 9884=5 Enjoy, this is quite interesting.
Submitted by Ravi
Doable
4.0
2 479 The Bookworm
Looking onto a shelf you see three books each labeled Volume 1, Volume 2, and Volume 3 respectively. Each book is 2.5 inches thick; that is the pages are 2 inches, and each cover .25 inches. A bo ...
Submitted by Aakash
Doable
5.3
2 2 Farmer's Market
You’re a farmer. You’re going to a market to buy some animals. On the market there are 3 types of animals for sale. You can buy: Horses for £10 each, goats for £1 each and ducks, you get 8 of these ...
Submitted by Aakash
Doable
4.7
1 4 3 Painted Ladies
There are 3 smart old ladies standing in a desert such a way that each lady can see the other two. Each of the 3 ladies has paint on her face. Seeing this, all three ladies begin laughing. After a wh ...
Submitted by Ravi
Doable
6.0
1 1 Find these Hollywood movies based on the title styles
Are you a movie buff ! Find these Hollywood movies based on the title styles !!
Doable
6.0
1 1 The fisherman and the Hunter
The are two men that always tell the truth except for the days when they are lying. The fisherman lies on Monday, Tuesday and Wednesday. The Hunter lies on Thursday, Friday and Saturday. Today the ...
Submitted by Valentin
Easy
3.0
1 8 Parodoxical Statements from Life
Nobody goes to that restaurant; it’s too crowded. Don’t go near the water ’til you have learned how to swim. The man who wrote such a stupid sentence can not write at all. If you get this messa ...
paradox Submitted by Ravi
Doable
5.2
1 2 Random Puzzle
Here’s something I heard from a friend, I thought it was appropriate. What do you call a 4 foot tall fortune teller who is wanted by the law? Good luck.
riddle funny Submitted by Ravi
Hard
7.3
1 3 Classic Knights & Knaves
Raymond Smullyan has made a career of writing logic problems. His most famous have to do with a mythical island of Knights and Knaves. Knights always tell the truth, and Knaves always lie. As you a ...
Submitted by Ravi
Doable
5.5
1 Neat twist on hat problem!
There are 100 people standing in a circle. Each person is given one hat to wear. A hat is either colored red or blue. A person cannot see his own hat color, but he can see the colors of the hats of all ...
logic Submitted by Simon
Doable
6.0
1 3 Greatest Area
A farmer challenges an engineer, a physicist, and a mathematician to fence off the largest amount of area using the least amount of fence. The engineer made his fence in a circle and said it was th ...
Submitted by Valentin
Doable
5.0
1 4 interesting visual puzzle
I've made this puzzle myself so I don't know if it's fair Hint: you might need a pencil and paper and look at the problem through a different perspective
Submitted by soni
Hard
10.0
1 2 Running Race
Phil and Sal race each other for 100 yards. Sal wins by 10 yards. They decide to race again, but this time, to even things up, Sal begins 10 yards behind the start line. Assuming that both run with t ...
Submitted by Aakash
Doable
3.3
1 8 Right or Left?
This is interesting. Look at the animation below. Do you see the girl spinning clockwise or counter-clockwise
Easy
3.0