Not 99 Riddle
Hint:
Swimming In The Ocean
Imagine you are swimming in the ocean and a bunch of hungry sharks surround you. How do you get out alive?
Hint:
The Train Of Love
A young man, living in Manhattan, New York, has two girlfriends. One lives to the North, in the Bronx, and the other lives to the South, in Brooklyn.
He likes both girls equally but can only visit one each weekend. He therefore leaves it to chance and takes the first train that arrives when he reaches the train station.
Even though the man arrives at a totally random time every Saturday morning and the Brooklyn and Bronx trains arrive equally often (every ten minutes), he finds himself visiting the girl in Brooklyn on average nine times out of ten. How could the odds so heavily favor taking the Brooklyn train?
He likes both girls equally but can only visit one each weekend. He therefore leaves it to chance and takes the first train that arrives when he reaches the train station.
Even though the man arrives at a totally random time every Saturday morning and the Brooklyn and Bronx trains arrive equally often (every ten minutes), he finds himself visiting the girl in Brooklyn on average nine times out of ten. How could the odds so heavily favor taking the Brooklyn train?
Hint: Think of a way the train schedules might favor one train over the other.
The Brooklyn train leaves exactly 1 minute before the Bronx train.
Let's say the Brooklyn train arrives at 09:00, 09:10, 09:20, etc. and the Bronx train arrives one minute after at 09:01, 09:11, 09:21, etc. Consider the ten minute interval from 09:00 to 09:10. If the man arrives between 09:00 and 09:01, the 09:01 Bronx train will be the first to arrive (assuming that he doesn't arrive at exactly 09:00). If the man arrives between 09:01 and 09:10, the 09:10 Brooklyn train will be the first to arrive. In any ten minute period, the Brooklyn train will be the first to arrive in nine of the ten minutes. Did you answer this riddle correctly?
YES NO
Let's say the Brooklyn train arrives at 09:00, 09:10, 09:20, etc. and the Bronx train arrives one minute after at 09:01, 09:11, 09:21, etc. Consider the ten minute interval from 09:00 to 09:10. If the man arrives between 09:00 and 09:01, the 09:01 Bronx train will be the first to arrive (assuming that he doesn't arrive at exactly 09:00). If the man arrives between 09:01 and 09:10, the 09:10 Brooklyn train will be the first to arrive. In any ten minute period, the Brooklyn train will be the first to arrive in nine of the ten minutes. Did you answer this riddle correctly?
YES NO
Accepting The Bet Riddle
There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.
If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.
Will you accept that bet?
If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.
Will you accept that bet?
Hint:
Yes, you should accept the bet. Simply because the odds of picking two relatively prime numbers are 60%. It is a win-win situation for you if you keep playing. Did you answer this riddle correctly?
YES NO
YES NO
Bones In Florida Riddle
Hint:
A Suitor To Portia Riddle
The casket scene in "The Merchant of Venice" contains several riddles. Which of these nobles was NOT a suitor to Portia? This odd-man-out noble might easily be confused with the contender who chose 'Who chooseth me shall gain what many men desire.'
Hint:
Clocking Out Riddle
Hint:
Not A Camera Riddle
I have a lid but Im not a can of paint
I have a lens but Im not a camera
Im in a socket but Im not a plug
I have an iris but Im not a bunch of flowers
I have lashes but I dont have a whip
What am I?
I have a lens but Im not a camera
Im in a socket but Im not a plug
I have an iris but Im not a bunch of flowers
I have lashes but I dont have a whip
What am I?
Hint:
Found In A Graveyard Riddle
I have writing on me but Im not a newspaper
I mark a spot but Im not a treasure map
I have names and dates on me but Im not a birth certificate
Im not needed if youre alive but Im not a coffin
I can be found in a graveyard but Im not a bunch of flowers
I'm a...
I mark a spot but Im not a treasure map
I have names and dates on me but Im not a birth certificate
Im not needed if youre alive but Im not a coffin
I can be found in a graveyard but Im not a bunch of flowers
I'm a...
Hint:
Fighting In A Truel
Mr. Black, Mr. Gray, and Mr. White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr. Black, who hits his shot 1/3 of the time, gets to shoot first. Mr. Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr. White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. All three competitors know one another's shooting odds. If you are Mr. Black, where should you shoot first for the highest chance of survival?
Hint: Think from the points of view of Mr. Gray and Mr. White, not just Mr. Black.
He should shoot at the ground.
If Mr. Black shoots the ground, it is Mr. Gray's turn. Mr. Gray would rather shoot at Mr. White than Mr. Black, because he is better. If Mr. Gray kills Mr. White, it is just Mr. Black and Mr. Gray left, giving Mr. Black a fair chance of winning. If Mr. Gray does not kill Mr. White, it is Mr. White's turn. He would rather shoot at Mr. Gray and will definitely kill him. Even though it is now Mr. Black against Mr. White, Mr. Black has a better chance of winning than before. Did you answer this riddle correctly?
YES NO
If Mr. Black shoots the ground, it is Mr. Gray's turn. Mr. Gray would rather shoot at Mr. White than Mr. Black, because he is better. If Mr. Gray kills Mr. White, it is just Mr. Black and Mr. Gray left, giving Mr. Black a fair chance of winning. If Mr. Gray does not kill Mr. White, it is Mr. White's turn. He would rather shoot at Mr. Gray and will definitely kill him. Even though it is now Mr. Black against Mr. White, Mr. Black has a better chance of winning than before. Did you answer this riddle correctly?
YES NO
Knights Of The Round Table Riddle
King Arthur, Merlin, Sir Lancelot, Sir Gawain, and Guinevere decide to go to their favorite restaurant to share some mead and grilled meats. They sit down at a round table for five, and as soon as they do, Lancelot notes, "We sat down around the table in age order! What are the odds of that?"
Merlin smiles broadly. "This is easily solved without any magic." He then shared the answer. What did he say the odds were?
Merlin smiles broadly. "This is easily solved without any magic." He then shared the answer. What did he say the odds were?
Hint: Does it matter if they are sitting clockwise or counterclockwise? Or where the oldest sits?
The odds are 11:1. (The probability is 1/12.)
Imagine they sat down in age order, with each person randomly picking a seat. The first person is guaranteed to pick a seat that "works". The second oldest can sit to his right or left, since these five can sit either clockwise or counterclockwise. The probability of picking a seat that works is thus 2/4, or 1/2. The third oldest now has three chairs to choose from, one of which continues the progression in the order determined by the second person, for a probability of 1/3. This leaves two seats for the fourth oldest, or a 1/2 chance. The youngest would thus be guaranteed to sit in the right seat, since there is only one seat left. This gives 1 * 1/2 * 1/3 * 1/2 * 1 = 1/12, or 11:1 odds against. Did you answer this riddle correctly?
YES NO
Imagine they sat down in age order, with each person randomly picking a seat. The first person is guaranteed to pick a seat that "works". The second oldest can sit to his right or left, since these five can sit either clockwise or counterclockwise. The probability of picking a seat that works is thus 2/4, or 1/2. The third oldest now has three chairs to choose from, one of which continues the progression in the order determined by the second person, for a probability of 1/3. This leaves two seats for the fourth oldest, or a 1/2 chance. The youngest would thus be guaranteed to sit in the right seat, since there is only one seat left. This gives 1 * 1/2 * 1/3 * 1/2 * 1 = 1/12, or 11:1 odds against. Did you answer this riddle correctly?
YES NO
The Prime Number Riddle
Two hundred people in an auditorium are asked to think of a single digit number from 1 to 9 inclusive and write it down. All those who wrote down a prime number are now asked to leave. Ninety people remain behind in the hall. How many of these are expected to have written down an odd number?
Hint: Remember that 1 is not a prime number.
Those that remain behind must have written {1,4,6,8,9} and from this only {1,9} are odd. The probability of an odd number is thus 2/5.
Expected number of odds is 2/5 * 90 = 36 Did you answer this riddle correctly?
YES NO
Expected number of odds is 2/5 * 90 = 36 Did you answer this riddle correctly?
YES NO
Chickens Playing Hide And Seek
Hint:
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