How to Prepare for Placements [PART 1]

Placement preparation can be divided into two parts-  general placement preparation and company specific preparation. In this blog we will focus on general placement preparation. What do you want to do? Having clarity about your interests and future possibilities is very important. Ideally you should have focussed on this much earlier. Do you want to … Read more

Three choices with a Coin

Question: At a restaurant, how could you choose one out of three desserts with equal probability with the help of a single coin (could be biased)? Answer: If the coin were not biased we could toss the two times and get the following events. Event Decision HH Choose first dessert HT Choose second dessert TH … Read more

Three Machine Guns

Question: A large group of zombies are coming towards you and there are three machine guns near you. Each machine gun has a different probability of firing bullets (say gun no 1 fires 1 bullet properly out of n bullets, on an average). You can operate one gun at a time and you do not … Read more

Three Hats Puzzle

Question: Three people enter a room and have a green or blue hat placed on their head. They cannot see their own hat, but can see the other hats. The colour of each hat is purely random. All hats could be green, or blue, or 1 blue and 2 green, or 2 blue and 1 … Read more

Unfaithful Husband Puzzle

Question: A certain town has 100 married couples (husband and wife only). Everyone in the town lives by the following rule: If a husband cheats on his wife, the husband is executed (killed) in the following night if his wife get to know out about him (He may enjoy only as long as his wife … Read more

Drunk Man Puzzle

Question: There is a drunk man who is standing at the edge of the cliff. One step forward would send him over the edge. He takes random steps, either towards or away from the cliff. At any step, his probability of taking a step away is 2/3 and a step towards the cliff is 1/3. … Read more

The Fox and the Duck

Question: A duck, that is being chased by a fox, saves itself by sitting at the centre of circular pond of radius r. The duck can fly from land but cannot fly from the water. Furthermore, the fox cannot swim. The fox is four times faster than the duck. Assuming that the duck and fox … Read more

Birthday Pairings

What is the least number of persons required if the probability exceeds 1/2 that two or more of them have same birthday? (Year of birth need not match, and ignore leap year). Let total number of persons be n, P be the probability that all persons have different birthdays. If there are two persons, the … Read more

N Consecutive Heads

Find expected number of coin tosses to get n consecutive heads. Let En denote the expected number of tosses to get n consecutive heads. Now if we get one more head after 𝐸n-1, then we have n consecutive heads or if it is a tail the we have to repeat the procedure again. This En … Read more

Egg Dropping Puzzle

Question: Figure out the highest floor of a 100-floor building an egg can be dropped without breaking, given two eggs. You are to determine the minimum number of attempts required in the worst case scenario to find the critical floor. Answer: Following are the logical assumptions that can be made- If the egg doesn’t break at a certain … Read more

Copy link