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

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 8 Survivor There are 1500 people sitting around a circular table. They are numbered in a regular manner (1 to 1500 along the table). Now, the 1st person gets a sword and kills the 2nd person. He then gives the s ... Submitted by Shaheen Hard 8.5 6 Binary 5 digits What is the base 10 equivalent of the highest 5 digit binary number? Submitted by Heather Moore Easy 2.0 2 How far can you go? You have a 4 wheels car and a spare tire in the trunk. The tire being used will be worn off for 1/4 part of it per mile (completely wear out for 4 miles) How to make use of the spare tire to go as fa ... Submitted by MoralMachine Doable 5.2 4 Cut the pizza into 11 equal slices with a wrist watch Tools: (1) A wrist watch and (2) a normal knife Goal: Slice a pizza into 11 equal pieces Submitted by MoralMachine Doable 6.0 13 Black and White Hats There are 100 prisoners in jail. Their guards decide to play a game with them. Here's what happens: 1) The prisoners are lined up in a single file, front to back, such that the prisoner at the back of ... Submitted by Aakash Hard 8.5 5 Lab Rat on the Run Consider a lab rat in a maze. There are four paths that can be taken with equal probability. Path A leads to exit in 5 minutes. Path B leads back to start and takes 8 minutes. Path C leads to exit in 3 ... Submitted by Yiğit Oktar Doable 6.0 2 What is the sum of 1+2+3+4+5 . . . (forever)? What is the sum of 1 + 2 + 3 + 4 . . . all the way to infinity? Submitted by Tarun245 Hard 8.0 3 Tooth Paste, : Profit There are 2 Persons, Who Saves Money. One person Bought a tooth Paste of 100 gms, for Rs. 40. The second person Buys, Two 50 gms for Rs. 20 each. at same shop, the same company of Pastes. No Extra past ... Submitted by Sachin Prabhu Doable 6.0 3 Brain Teaser 56 Answer Yes or No to this brain teaser Submitted by raiseyouriq 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 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 1 How many?2 How many people contribute to MindCipher? Submitted by Gene Easy 2.0 4 There are only 4 circles and none of them touch Source: reddit. Submitted by Ravi Easy 2.0 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 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 +- · / (basic arithmetic operator ... Submitted by Doodz Hard 10.0