Welcome to MindCipher, a social repository of the world's greatest brain teasers, logic puzzles and mental challenges.

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 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 ... Submitted by Simon Doable 6.0 1 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 2 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 1 4 buttons and a light bulb There are two rooms, in one room there is a light bulb, and in the other there is a round table, with 4 buttons arragned in a square on it. Each button may be on or off, and the light bulb will be on o ... Submitted by TulkinRB Hard 8.0 3 100 kg bag of potatoes if you have a 100kg bag of potatoes, that are 99% water, they're left out in the sun and dry up a bit, so it's now 98% water, how heavy is the bag of potatoes? Submitted by chuck3r Doable 5.0 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 6 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 ... Submitted by Rifqi Ardia Ramadhan Easy 2.7 5 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 ... Submitted by Rifqi Ardia Ramadhan Doable 6.0 5 Sand Timer Puzzle You have two sand timers with you. One can measure 7 minutes and the other sand timer can measure 11 minutes. This means that it takes 7 minutes for the sand timer to completely empty the sand from one ... Submitted by Rohit Gurjar Doable 5.0 4 No if() no abs()! This is inspired by the puzzle "No if() only abs()" : Given two variable a and b, construct a function f(a,b) which return the maximum one in {a,b}. You can only use +- ยท / (basic arithmetic operator ... Submitted by Doodz Hard 10.0 5 12 balls part 2 You have 12 identical RUBBER balls each of 10 grams and one of 9 grams.You have three weighs of a weighing machine (not a balance scale) to determine which ball is different and whether it is heavier o ... Submitted by Vishal barot Doable 3.3 4 There are only 4 circles and none of them touch Source: reddit. Submitted by Ravi Easy 2.0 1 How many?2 How many people contribute to MindCipher? Submitted by Gene Easy 2.0 3 How many? As I was going to St. Ives, I met a man with seven wives. Each wife had seven sacks. Each sack has seven cats. Each cat had seven kits. Kits, cats, sacks, and wives, How many were going to St. Ives? ... Submitted by Gene Easy 2.8 6 Death by drawing? You are a prisoner in a strange foreign land, and a random drawing will decide your fate. You are given 2 bags, 10 white marbles, and 10 black marbles. You are to place the marbles in the bags in any a ... Submitted by Gene Doable 4.4