All Puzzles
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( ) + ( ) + ( ) + ( ) + ( ) = 30
This is what you have for equation. The following are the numbers that you can use to fill in the brackets:
1, 3, 5, 7, 9, 11, 13 and 15You can repeat the numbers if required. The resulting sum should be 30.
This question appeared in the UPSC final examination in December 2013. Out of all the people who appeared, only one guy was able to solve this namely Gaurav Agarwal.Can you solve it?
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Rohan was in an interview. The interviewer told his that this was his last question and then he asked him to point at the exact center of the table on which his resume was kept.
He gave an answer after which he was selected. Can you think of what happened inside the interview room?
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There is a building of 100 floors If an egg drops from the Nth floor or above it will break. If it’s dropped from any floor below, it will not break. You’re given 2 eggs. Find N, while minimizing the number of drops for the worst case.
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There is a lightbulb (incandescent, it’s currently off) in an upstairs room. You are downstairs, standing next to a panel of three light switches (all of them in the off position). One of them controls the lightbulb. The other two don’t do anything. You must figure out which switch controls the bulb, with some restrictions.
1) You can do whatever you want to the lightswitches, as long as it’s either turning them on or turning them off.
2) After fiddling with the lightswitches, you can go upstairs and check the bulb.
3) You cannot see the bulb nor any light shining from it from where you’re initially standing.
4) You cannot make multiple trips up and down the stairs.
5) The lamp is in the ceiling and you don’t have a ladder.
6) You are a mutant with 15-foot-long arms, so #5 is moot.So, you fiddle with the switches, you walk upstairs and check the bulb, and then you immediately decide which switch controls the bulb.
How do you do it?
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You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different.
How do you measure 45 minutes?
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I ask Alex to pick any 5 cards out of a deck with no Jokers.
He can inspect then shuffle the deck before picking any five cards. He picks out 5 cards then hands them to me (Peter can’t see any of this). I look at the cards and I pick 1 card out and give it back to Alex. I then arrange the other four cards in a special way, and give those 4 cards all face down, and in a neat pile, to Peter.
Peter looks at the 4 cards i gave him, and says out loud which card Alex is holding (suit and number). How?
The solution uses pure logic, not sleight of hand. All Peter needs to know is the order of the cards and what is on their face, nothing more.
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Four angels sat on the Christmas tree amidst other ornaments. Two had blue halos and two – yellow. However, none of them could see above his head. Angel A sat on the top branch and could see the angels B and C, who sat below him. Angel B, could see angel C who sat on the lower branch. And angel D stood at the base of the tree obscured from view by a thicket of branches, so no one could see him and he could not see anyone either.
Which one of them could be the first to guess the color of his halo and speak it out loud for all other angels to hear?View SolutionSubmit Solution- 1,452.0K views
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Three Palefaces were taken captive by a hostile Indian tribe. According to tribe’s custom they had to pass an intelligence test, or die.
The chieftain showed 5 headbands – 2 red and 3 white. The 3 men were blindfolded and positioned one after another, face to back. The chief put a headband on each of their heads, hid two remaining headbands, and removed their blindfolds. So the third man could see the headbands on the two men in front of him, the second man could see the headband on the first, and the first could not see any headbands at all.
According to the rules any one of the three men could speak first and try to guess his headband color. And if he guessed correctly – they passed the test and could go free, if not – they failed. It so happened that all 3 Palefaces were prominent logicians from a nearby academy. So after a few moments of silence, the first man in the line said: “My headband is …”.
What color was his head band? Why?View SolutionSubmit Solution- 1,450.7K views
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After losing the “Spot on the Forehead” contest, the two defeated Puzzle Masters complained that the winner had made a slight pause before raising his hand, thus derailing their deductive reasoning train of thought. And so the Grand Master vowed to set up a truly fair test to reveal the best logician amongst them.
He showed the three men 5 hats – two white and three black. Then he turned off the lights in the room and put a hat on each Puzzle Master’s head. After that the old sage hid the remaining two hats, but before he could turn the lights on, one of the Masters, as chance would have it, the winner of the previous contest, announced the color of his hat. And he was right once again.
What color was his hat? What could have been his reasoning?View SolutionSubmit Solution- 1,453.2K views
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