Welcome to MindCipher, a social repository of the world's greatest brain teasers, logic puzzles and mental challenges.
8 3 The Tallest Mountain
A man approaches you with a very enigmatic look on his face. He asks your for a bit of your time and if you could answer a quick question for him. He asks: “Before Mt. Everest was discovered, which w ...
riddle Submitted by Ravi
Easy
2.3
4 1 What Number Is It?
So there are two students, that play a game with their teacher. They have 10 cards, each card is numbered 1,2,3,...,9,10. And then their teacher gives them two cards that is consecutive. For example, o ...
Easy
2.0
4 3 The Middle of Nowhere
What is in the middle of "nowhere"? The answer is indisputable, and not based on some philosophy.
riddle Submitted by Aakash
Easy
2.4
1 1 Use your mobile
In this puzzle I have given a message in a coded language. try to solve it. Message: 936382004221833200416381004381 Hint is in the title of this puzzle
Submitted by Rohan Umesh
Doable
6.0
3 2 Brain Teaser 56
Answer Yes or No to this brain teaser
Easy
2.8
8 5 Prisoners and hats
100 prisoners are standing in a line each 1 seeing the back of the ones in front of him. Each prisoner is given a black or a white hat. If they can guess the color of their hat they can go away freel ...
logic brain teaser Submitted by Valentin
Hard
8.5
10 3 Measuring Up
You have a 3 and a 5 litre water container, each container has no markings except for that which gives you its total volume. You also have a running tap. You must use the containers and the tap in su ...
logic brain teaser Submitted by Ravi
Easy
3.1
10 2 Two Trains
Two trains (Train A and B) with 200 km between them are travelling towards each other at 100km/h. A mosquito, initially standing on the front of Train A, starts travelling towards Train B at 150km/h. O ...
Math physics rates Submitted by Ravi
Doable
4.5
12 1 Choose the Next Letter
Choose the next letter in the sequence: O T T F F S S ?
logic patterns sequences Submitted by Ravi
Doable
4.0
7 5 Clock Works - Google Interview Question
How many degrees are there in the angle between the hour and minute hands of a clock when the time is a quarter past three?
Easy
3.1
7 2 Burning Rope
There are two lengths of rope. Each one can burn in exactly one hour. They are not necessarily of the same length or width as each other. They also are not of uniform width (may be wider in middle th ...
Submitted by Ravi
Doable
4.3
7 10 Non-Adaptive 12 Identical Balls
Okay - so I posted this puzzle to reddit a few weeks ago and one guy had the following comment: Same problem, but your solution must be non-adaptive. IOW, specify the weighings that you will make up f ...
Math logic unsolved Submitted by Aakash
Hard
9.0
5 1 Age of Three Kids
One day, a guy from census come into a house. When he rings the bell, a lady comes out. He then asks how many people lives in her house, and their age. And then she says: I am 45 years old. I have thr ...
Doable
6.0
8 8 Interview Question - Databases
This is a common interview question at companies like Google and Amazon: “Explain a database in three sentences to your eight-year-old nephew.” This question has an infinite number of solutions. Fee ...
Easy
2.7
6 8 Happy Handshaking
Jack and his wife went to a party where four other married couples were present. Every person shook hands with everyone he or she was not acquainted with. When the handshaking was over, Jack asked ev ...
Submitted by Valentin
Hard
8.0