Logic Puzzles

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?
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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?
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A bunch of men are on an island, A genie comes down and gathers everyone together and places a magical hat on some people’s heads (i e , at least one person has a hat). The hat is magical: it can be seen by other people, but not by the wearer of the hat himself. To remove the hat, those (and only those who have a hat) must dunk themselves underwater at exactly midnight. If there are n people and c hats, how long does it take the men to remove the hats? The men cannot tell each other (in any way) that they have a hat.
Note: Genie does not tell how many hats she has put.
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One morning I was on my way to puzzle fry market and met a man who had 4 wives. Each of the wives had 4 bags containing 4 dogs and each dog had 4 puppys.
Taking all things into consideration how many were going to the puzzle fry market?View SolutionSubmit Solution 1,514.0K views
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We have three containers which hold 19, 13 and 7 ounces of liquid respectively. The 19 ounce container is empty but the 13 and 7 ounce containers are full. How can we measure out 10 ounces by using only the three above mentioned containers?
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New Zealand to Tahiti. I was curious to look around the ship one day and in the boiler room I asked a man how old the ship was. He smiled and replied me in this way: ‘The ship is twice as old as its boiler was when the ship was as old as the boiler is now. And the combined age of the ship and the boiler is thirty years.’
Can you figure out what is the age of the ship and of the boiler?View SolutionSubmit Solution 1,513.4K views
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The product of three consecutive numbers when divided by each of them in turn, the sum of the three quotients will be 74.
What are the numbers?View SolutionSubmit Solution 1,512.7K views
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One day when I was walking on the road in New Delhi, a group of boys approached me for donation for their poor boys’ fund. I gave them a rupee more than half the money I had in my purse. I must have walked a few more yards when a group of women approaphed me for donations for an orpbange. I gave them two rupees more than half the money I had in my purse. Then, after a few yards I was approached by a religious group for a donation to the temple they were building. .1 gave them three rupees more than half of what I had in my purse.
At last when returned to my hotel room, I found that I had only one rupee remaining in my purse.
How much money did I have in my purse when I started?View SolutionSubmit Solution 1,512.6K views
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An unscrupulous trader decided to make some extra profit on Coffee. He bought one type of coffee powder at Rs. 32 a kilo and mixed some of it with a better quality of coffee powder bought at Rs. 40 a kilo, and he sold the blend at 43 a kilo. That gave him a profit of 25 per cent on the cost.
How many kilos of each kind must he use to make a blend of a hundred kilos weight?View SolutionSubmit Solution 1,516.4K views
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A factory manufacturing flywheels for racing cars has ten machines to make them. The manufacturer knows the correct weight for a flywheel.
However, one day one of the machines begins to produce faulty parts—either overweight or underweight.
How can the manufacturer find the faulty machine in only two weighings?View SolutionSubmit Solution 1,514.0K views
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