1. 5 men in a boat: 5 thieves,A B C D E are travelling in a boat with 100 gold coins. they have to divide these coins among them according to this way: Each thief starting from A to E should suggest a way (how many coins each shud get) . If this suggestion gets >= 50 % of vote (among the people in the boat, including the vote of suggested person) that suggestion can b followed, or the suggesting person must die. all the five are brilliant & they value their life first, then they try getting coins & then they try that others are killed. Now, 'A' suggests a way and gets >=50 % of vote and they share the coins in that fashion. what is the suggestion?

2. 1000 bulbs: there are 1000 bulbs in a room and the switches for these bulbs are in a different room arranged in a random fashion. After changing the status of the switches, u can see the status of the bulbs only by entering into the room with bulbs.u have to find an optimum strategy for matching the switches with the corresponding bulbs so that the number of times u enter into the room is minimum.

3. Six men in a boat: Similar rules as that of the first problem (5 men in a boat) , here there r 6 men with 1 coin. what is the suggestion by the 1st person to save his life?

4. 12 balls: there are 12 similar balls.except 1 all are equal in weight which may be less or more in weight. u have a balance without weights. only by using the balance 3 times u have to find the defective ball.

5. 10 boxes : there are 10 boxes with many chocolates in each. All chocolates are 10 grams in weight except those in one box. all the chocolates in the defective box are 9 grams in weight. now, using a balance & all possible weights u have to find the defective box in only one measurement.

6. 1 hour rope: u have a rope that would burn exactly for 1 hr if fired at one end. the burning rate is not uniform. u have to use this to measure exactly 1/n hrs. u cant cut the rope lengthwise.

*new* 7. N hats n colours:The warden meets with 'N' new prisoners when they arrive. He tells them, "You may meet today and plan a strategy. But after today, you should have no communication with one another. tomorrow I will give u 'N' hats one for each whose color will b one of these 'n' colors" and list's the 'n' colors. each prisoner can see all the hats except his own hat.the warden will call a prisoner in random and ask the color of hat in his head. if he answers correct he will b left free, or he will b killed. all the other prisoners could see and hear the answer. what is the strategy that they should plan so that the number of prisoners dieing is minimum?

*new* 8. Two bottles: You have two similar bottles of equal strength. u have to find the optimum strategy for finding the strength of the bottle in terms of number of floors from which it can be dropped without breaking it of a 100 storey building, so that the number of times u drop the bottle is minimum. * if u drop a bottle from 10th floor without breaking then it will not break for all floors <= 10. *

9. King with wine bottles: A king has 1000 bottles of delightful and very expensive wine. one bottle has been poisoned. The poison is so strong that even if diluted 1,000,000 times it would still kill the king. furthermore, it takes one month to have an effect. the king decides he will get some of the prisoners in his vast dungeons to drink the wine. How is the king to act to kill less prisoners and to find the poisoned bottle in minimum time?

10. Modified 12 balls: The question is same as 12 balls puzzle ( puzzle no. 4 ). But, u have to find the strategy so that the balls to b placed during the weighing does not depend on the result of previous weighing. Number the balls frm 1 - 12 and say the numbers of the balls to b placed in each pane for all the 3 weighings initially. This will b more suitable for computer programming.

11. Markings over the head: There is a group of devotees for a saint and they attend a meeting everyday. The saint makes a mark in few of their head and says that if they found that their head has a marking, they shud not come for the next day's meeting. Each devotee can see others head, but not his own. They cannot communicate with each other. all the devotees are attending the meeting for 5 days. on the 6th day, people having the markings over their head did on attend the meeting, while the other continuing. how many markings did the saint make?

*new* 12. Five card trick: Myself and my friend played a trick on a third person- The third person will take 5 cards from a standard deck of 52 cards and give to my friend. My friend will see all the cards(without showing them to me) and give me four cards. By looking at these four cards, I will guess the fifth card that is in my friends hand. So, What is the strategy that I and my friend has followed to get it correct everytime? There may be various strategies for this puzzle, the simplest will be the best!

*new* 13. There are 25 horses, each one runs at constant and different speed. You need to find out the minimum races it takes to find out the first, second and third fastest horses from them. Each horse race can only have 5 horses and you don't have a stop watch to time it. (First tryout the same for 10 horses..)