Zs Associate Interview Puzzles

The Pill Problem | Hard Brain Teaser

Man and 3 Pill Puzzle

Puzzle: This is very hard brain teaser. A man has a medical condition that requires him to take two kinds of pills, call them P1 and P2. The man must take one P1 pill and one P2 pill each day, or he will die. If he takes more than 1 pill of the same kind Read More →

3 Doors and Angel

Problem : You are given a choice of three doors by an Angel. You can choose only one of the doors among the three. Out of these three doors two contains nothing and one has a jackpot. After you choose one of the doors angel  reveals one of the other two doors behind which there Read More →

3 Mislabeled Jars

3 mislabeled jars of Apple and Orange

Puzzle: This problem is also called Jelly Beans problem. This is the most commonly asked interview puzzle. You have 3 jars that are all mislabeled. One jar contains Apple, another contains Oranges and the third jar contains a mixture of both Apple and Oranges. You are allowed to pick as many fruits as you want Read More →

Ant and Triangle Problem

Ants and triangle puzzle

Puzzle: Three ants are sitting at the three corners of an equilateral triangle. Each ant starts randomly picks a direction and starts to move along the edge of the triangle. What is the probability that none of the ants collide? Puzzle Solution: So let’s think this through. The ants can only avoid a collision if Read More →

10 identical bottles of pills

This is a very popular brain teaser with many companies. Problem : We have 10 identical bottles of identical pills (each bottle contain hundred of pills). Out of 10 bottles 9 have 1 gram of pills but 1 bottle has pills of weight of 1.1 gram. Given a measurement scale, how would you find the Read More →