Five Weeks Old Riddle
Born at the same time as the world, destined to live as long as the world, and yet never five weeks old. What is it?
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Measuring Riddle
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Faulty Puzzle Riddle
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Not My Sisters Or Brother Riddle
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Always Before You Riddle
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Neither Inside Nor Outside Riddle
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Always Right Riddle
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Always Overlooked Riddle
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Pills A And B Riddle
You have two bottles of pills marked with the label A and B. The pills are identical. The doctor has asked you to take one A pill and one B pill daily. You cant take more or less than that.
While taking out the pills one day, you took out one pill from A and by mistake took out two from B. You have no idea which pill is which now.
You cant throw away the expensive pills. What will you do now?
While taking out the pills one day, you took out one pill from A and by mistake took out two from B. You have no idea which pill is which now.
You cant throw away the expensive pills. What will you do now?
Hint:
Cut each of the three pills in half and put each half in two piles. Now, each of the two piles will contain half of pill A and two halves of pill B.
Take one pill A and cut into half and put the two halves in the two piles. Now, each pile will have two halves of pill A and two halves of pill B which means one pill A and one pill B. You can take one pile today and one pile the next day. Did you answer this riddle correctly?
YES NO
Take one pill A and cut into half and put the two halves in the two piles. Now, each pile will have two halves of pill A and two halves of pill B which means one pill A and one pill B. You can take one pile today and one pile the next day. Did you answer this riddle correctly?
YES NO
Switch Or Stick Riddle
There are three doors: Door 1, Door 2, and Door 3. Behind one of these doors lies eternal bliss, but behind the others lies eternal despair. You are allowed to choose any door, and you pick Door 1. Suddenly, Door 3 is swung open and revealed to be despair! You are give another choice: you may stick with the door you chose (1) or switch to the other (2). What should you do?
Hint:
The answer may surprise you: switch. Due to something called the Monty Hall Paradox, you will statistically have a better chance of making the "correct" choice. The concept is as follows:
Door 1 Door 2 Door 3
All have an equal chance to be correct:
Door 1: 1/3 Door 2: 1/3 Door 3: 1/3
After choosing Door 1, the remaining two have a 2/3 chance of containing the right choice:
Door1: 1/3 Doors 2 3: 2/3
If Door 3 is removed, the probability does not shift to 50:50. Instead, it is:
Door 1: 1/3 Door 2: 2/3
Thus, you should switch. Did you answer this riddle correctly?
YES NO
Door 1 Door 2 Door 3
All have an equal chance to be correct:
Door 1: 1/3 Door 2: 1/3 Door 3: 1/3
After choosing Door 1, the remaining two have a 2/3 chance of containing the right choice:
Door1: 1/3 Doors 2 3: 2/3
If Door 3 is removed, the probability does not shift to 50:50. Instead, it is:
Door 1: 1/3 Door 2: 2/3
Thus, you should switch. Did you answer this riddle correctly?
YES NO
Swinging At The Park Riddle
A man and his 6 year old daughter are swinging together at the park. Each is on a separate, identical swing. The man has three times the mass of the child.
Which swings faster? And more importantly, why?
Which swings faster? And more importantly, why?
Hint:
The speed at which a pendulum swings is called the period and given by the equation:
2 x pi x square root of (length of rope from fulcrum to Center of Mass divided by gravity)
Since gravity is constant, the only thing that effects the period is the length of rope. In the above scenario, you assume the man is taller then the child. Therefore his center of mass is higher. This makes the distance between the fulcrum to the center of mass shorter then for the child. The man swings faster. Did you answer this riddle correctly?
YES NO
2 x pi x square root of (length of rope from fulcrum to Center of Mass divided by gravity)
Since gravity is constant, the only thing that effects the period is the length of rope. In the above scenario, you assume the man is taller then the child. Therefore his center of mass is higher. This makes the distance between the fulcrum to the center of mass shorter then for the child. The man swings faster. Did you answer this riddle correctly?
YES NO
Counterfeit Coins Riddle
You are given eight coins and told that one of them is counterfeit. The counterfeit one is slightly heavier than the other seven. Otherwise, the coins look identical. Using a simple balance scale, how can you determine which coin is counterfeit using the scale only twice?
Hint:
First weigh three coins against three others. If the weights are equal, weigh the remaining two against each other. The heavier one is the counterfeit. If one of the groups of three is heavier, weigh two of those coins against each other. If one is heavier, its the counterfeit. If theyre equal weight, the third coin is the counterfeit. Did you answer this riddle correctly?
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YES NO
Fastest Horse Riddle
The London Racetrack needs to submit its 3 fastest horses to the Kentucky Derby out of 25 horses. However, all of their information was lost and they don't know any of the horse's times. Similarly, they all look identical so they can't remember who's fastest.
They can only race 5 horses at once, so what is the fewest number of races they can conduct to find the 3 fastest horses?
They can only race 5 horses at once, so what is the fewest number of races they can conduct to find the 3 fastest horses?
Hint:
First you divide the 25 horses into 5 groups of 5. You conduct the 5 races and take all of the fastest horses in those races and have a race with them, giving you the fastest horse. Then you take the remaining 24 horses (excluding the fastest) and remove the 4th and 5th horses in the first set of 5 races (since they definitely have 3 horses faster than them), leaving you with 14 horses. Next you can remove all of the horses that were beat in the preliminary race by the horses that got 4th and 5th in the championship race, leaving you with 8 horses. Finally, you can remove the horses that remain that lost to the 3rd place horse in the final race in the preliminary race and the horse that got 3rd in the preliminary to the horse that got 2nd in the championship race, leaving you with 5 horses.
You can then run a final race where the 1st and 2nd place horses are the 2nd and 3rd fastest. Then you know the 3 fastest horses. Did you answer this riddle correctly?
YES NO
You can then run a final race where the 1st and 2nd place horses are the 2nd and 3rd fastest. Then you know the 3 fastest horses. Did you answer this riddle correctly?
YES NO
Rope Burn Riddle
You have two ropes. Each rope takes one hour to burn. These ropes are not identical, nor are they uniform; i.e. it does not necessarily take half an hour for half the rope to burn (if you have trouble visualizing this, imagine a rope of varying thickness across its length). With only these two ropes and a way to light them, how do you measure out 45 minutes?
Hint: You can light multiple ends and/or multiple ropes at the exact same time.
Light both ends of one rope, and only one end of the other rope. This will cause the first rope to burn out in 30 minutes. When the first rope burns out, there will be 30 minutes left on the second rope. So then, light the other end of the second rope, and the rest of it will burn out in 15 minutes. 30 + 15 = 45 minutes. Did you answer this riddle correctly?
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YES NO
A Blind Man Gets Marooned In A Desert Riddle
A blind man gets marooned in a desert. He has 2 red pills and 2 blue pills with him. The pills are identical in size and shape. To stay alive, he must take 1 red pill and 1 blue pill.
Any other combination of pills would bring him certain death. How can the blind man ensure that he takes exactly 1 red pill and 1 blue pill?
Any other combination of pills would bring him certain death. How can the blind man ensure that he takes exactly 1 red pill and 1 blue pill?
Hint:
The man will break each of the 4 pills in half and eat 1 half from each of the pills. Did you answer this riddle correctly?
YES NO
YES NO
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