How Many Times A Day?
Hint:
22 times: 12:00:00, 1:05:27, 2:10:55, 3:16:22, 4:21:49, 5:27:16, 6:32:44, 7:38:11, 8:43:38, 9:49:05, 10:54:33. Each twice a day. Did you answer this riddle correctly?
YES NO
YES NO
A Nose That Grows
Every time a man lies his nose grows to 150 percent of its size. Every time he tells the truth it shrinks to 50 percent of its size.
What will happen if he alternates between lies and the truth
What will happen if he alternates between lies and the truth
Hint:
For every pair of a truth and a lie his nose will shrink to 75 percent of its previous size prior to this truth and lie. So the correct answer is 0. As the number of times he tells a lie and the truth ((3/4)n) approaches infinity the length of his nose approaches 0. Did you answer this riddle correctly?
YES NO
YES NO
The Broken Grandfather Clock
A grandfather has a broken grandfather clock that is off by a minute every hour (too fast). He figures out a way, while keeping it running at the same rate, to make the clock say the correct time twice a day.
How could he do this?
How could he do this?
Hint:
The Tree And The Teacher Riddle
Hint:
Teacher's Dessert Riddle
Hint:
Dangerous Chemicals Riddle
There is a chemical that is very dangerous. If this chemical is inhaled, it may be fatal. Under certain conditions, contact with the skin can cause a burn. However, once a person's body becomes dependent on this chemical, prolonged separation from this chemical can cause death. However, even though many people know of this chemical, and it is found in nearly every drinking source, nothing is being done to try to get rid of it. Why is nothing being done about this chemical?
Hint: This is a real chemical. Think about everything that is being said.
No one does anything about it because the chemical is water. Did you answer this riddle correctly?
YES NO
YES NO
Outrunning A Train Riddle
Walking home one day, you take a short cut along the train tracks. The tracks cross a narrow bridge over a deep gorge. At the point you are 3/8 of the way across the bridge, you hear the train whistle somewhere behind you. You charge across the bridge, and jump off the track as the train is about to run you down. As it happens, if you had gone the other way, you would have reached safety just before being run over as well. If you can run ten miles per hour, how fast is the train moving?
Hint:
The train is moving at 40 miles per hour. Imagine that a friend is walking with you. When the train whistle blows, you head away from the train, he heads toward it. When he reaches safety, you will be 6/8 (or 3/4)of the way across the bridge, and the train will have just reached the bridge. For the train to cross 4/4 of the bridge in the time you cross the remaining 1/4, the train must be moving four times your speed. Did you answer this riddle correctly?
YES NO
YES NO
The Nonstop Trains Riddle
A nonstop train leaves Moscow for Leningrad at 60 mph. Another nonstop train leaves leningrad for Moscow at 40 mph. How far apart are the trains 1 hour before they pass each other?
Hint:
Dreams Of Guillotines Riddle
A lawyer argued for $1,000,000 damages based on the following claim: His client went to an art museum, where he saw a painting of Marie Antoinette on a guillotine. He fell asleep and dreamed of the painting. At the museums closing time, a guard tapped him on the neck just as he dreamed of the guillotine beheading Marie Antoinette. The tap provoked immediate cardiac arrest and a fatal heart attack immediately following, because he associated the tap with the guillotine blade.
The judge dismissed the case. Why?
The judge dismissed the case. Why?
Hint:
If the client died in his sleep, there would be no way of knowing what he was dreaming. Did you answer this riddle correctly?
YES NO
YES NO
Eating Burgers Riddle
How many burgers can 9 boys eat in 3 hours ?
Hint:
18
More hours => more burgers.
More boys => more burgers.
The time become twice (3 hours / 1.5 hours).
Boys become six times (9 / 1.5).
Number of burgers = 2 * 6 * Original(1.5)
= 18 Did you answer this riddle correctly?
YES NO
More hours => more burgers.
More boys => more burgers.
The time become twice (3 hours / 1.5 hours).
Boys become six times (9 / 1.5).
Number of burgers = 2 * 6 * Original(1.5)
= 18 Did you answer this riddle correctly?
YES NO
A Special Integer Riddle
A special integer exists in mathematics that shows a special property. If you subtract any number from that integer, the result will always be divisible by the successor of that number completely.
Do you know what that integer is ?
Do you know what that integer is ?
Hint:
The required integer is -1.
For an example, let us subtract 7 from -1.
-1 - 7 = -8
Now the successor of 7 is 8 and (-8) is exactly divisible by 8.
You can try that for any number and it will hold true. Did you answer this riddle correctly?
YES NO
For an example, let us subtract 7 from -1.
-1 - 7 = -8
Now the successor of 7 is 8 and (-8) is exactly divisible by 8.
You can try that for any number and it will hold true. Did you answer this riddle correctly?
YES NO
Two Fathers Two Sons Riddle
Hint:
A Rickety Bridge Riddle
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?
Hint:
17 mins.
The initial solution most people will think of is to use the fastest person as an usher to guide everyone across. How long would that take? 10 + 1 + 7 + 1 + 2 = 21 mins. Is that it? No. That would make this question too simple even as a warm up question.
Let's brainstorm a little further. To reduce the amount of time, we should find a way for 10 and 7 to go together. If they cross together, then we need one of them to come back to get the others. That would not be ideal. How do we get around that? Maybe we can have 1 waiting on the other side to bring the torch back. Ahaa, we are getting closer. The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let's put all this together.
1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across (done)
Total time = 2 + 2 + 10 + 1 + 2 = 17 mins Did you answer this riddle correctly?
YES NO
The initial solution most people will think of is to use the fastest person as an usher to guide everyone across. How long would that take? 10 + 1 + 7 + 1 + 2 = 21 mins. Is that it? No. That would make this question too simple even as a warm up question.
Let's brainstorm a little further. To reduce the amount of time, we should find a way for 10 and 7 to go together. If they cross together, then we need one of them to come back to get the others. That would not be ideal. How do we get around that? Maybe we can have 1 waiting on the other side to bring the torch back. Ahaa, we are getting closer. The fastest way to get 1 across and be back is to use 2 to usher 1 across. So let's put all this together.
1 and 2 go cross
2 comes back
7 and 10 go across
1 comes back
1 and 2 go across (done)
Total time = 2 + 2 + 10 + 1 + 2 = 17 mins Did you answer this riddle correctly?
YES NO
The Perfect Pill Riddle
The world is facing a serious viral infection. The government of various countries have issued every citizen two bottles. You as well have been given the same. Now one pill from each bottle is to be taken every day for a month to become immune to the virus. The problem is that if you take just one, or if you take two from the same bottle, you will die a painful death.
While using it, you hurriedly open the bottles and pour the tablets in your hand. Three tablets come down in your hand and you realize they look exactly the same and have same characteristics. You cant throw away the pill as they are limited and you cant put them back or you may put it wrong and may die someday.
How will you ensure that you are taking the right pill?
While using it, you hurriedly open the bottles and pour the tablets in your hand. Three tablets come down in your hand and you realize they look exactly the same and have same characteristics. You cant throw away the pill as they are limited and you cant put them back or you may put it wrong and may die someday.
How will you ensure that you are taking the right pill?
Hint:
You must put labels on the tablets as A and B before using. In that case, if you pour tablets together, you will get 3A, 2A 1B, 1A 2B or 3B. If they are from the same bottles you can take one from another bottle and save the remaining two for another day. If you get two from same and one from other, you can draw one from another bottle and you will have two pairs of which you can eat one and save the other. Did you answer this riddle correctly?
YES NO
YES NO
Person In The Painting Riddle
A man walks into an art gallery and concentrates on one picture in particular. The museum curator notices this and asks the man why he is so interested in that one painting. The man replies, "Brothers and sisters have I none, but that man's father is my father's son."
Who is in the painting?
Who is in the painting?
Hint:
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