Missing Dollar Riddle
Hint: Make a list of all of the people involved and how much money they ended up with/spent.
The $9 paid by each guest accounts for the $2 that went to the bellhop. So rather than adding $27 to the $2 kept by the bellhop, the $27 accounts for the bellhops money. The $27 plus the $3 kept by the guests does add up to $30. Did you answer this riddle correctly?
YES NO
YES NO
Prince Age Riddle
What are their ages?
Hint:
Current Future Past
Princess x 2z (x+y)/2
Prince y x z
I then created three equations, since the difference in their age will always be the same.
d = the difference in ages
x y = d
2z x = d
x/2 + y/2 z = d
I then created a matrix and solved it using row reduction.
x y z
1 -1 0 d
-1 0 2 d
.5 .5 -1 d
It reduced to:
x y z
1 0 0 4d
0 1 0 3d
0 0 1 5d/2
This means that you can pick any difference you want (an even one presumably because you want integer ages).
Princess age: 4d
Prince age: 3d
Ages that work
Princess:
4
8
16
24
32
40
48
56
64
72
80
Prince:
3
6
12
18
24
30
36
42
48
54
60 Did you answer this riddle correctly?
YES NO
Princess x 2z (x+y)/2
Prince y x z
I then created three equations, since the difference in their age will always be the same.
d = the difference in ages
x y = d
2z x = d
x/2 + y/2 z = d
I then created a matrix and solved it using row reduction.
x y z
1 -1 0 d
-1 0 2 d
.5 .5 -1 d
It reduced to:
x y z
1 0 0 4d
0 1 0 3d
0 0 1 5d/2
This means that you can pick any difference you want (an even one presumably because you want integer ages).
Princess age: 4d
Prince age: 3d
Ages that work
Princess:
4
8
16
24
32
40
48
56
64
72
80
Prince:
3
6
12
18
24
30
36
42
48
54
60 Did you answer this riddle correctly?
YES NO
Pinocchio Paradox Riddle
Hint:
His nose did grow when he said it would, but his nose is only supposed to grow when he lies, and his nose would grow even though he told the truth, and the paradox appears to exist again.
You can prove that's not true because he created a self fulfilling prophecy when he said his nose was going to grow bigger because saying that was saying he was going to lie.
In order to lie; he had to tell the truth, and say that he was lying, when he was really telling the truth, which would be a lie.
He did say he was lying because he said his nose was going to grow, and even though he said he was lying, he was actually telling the truth; which means he was lying about lying, or lying about not telling the truth.
His nose did grow, and he did tell the truth, but he said he was lying when he was telling the truth, which was the lie that made his nose grow.
Since his nose didn't grow after he told the truth, but after he lied about not telling the truth; the paradox doesn't exist.
That second answer actually works for both scenarios, where as the first answer only works for the first scenario, so I suppose you can say the second answer is the correct one. Did you answer this riddle correctly?
YES NO
You can prove that's not true because he created a self fulfilling prophecy when he said his nose was going to grow bigger because saying that was saying he was going to lie.
In order to lie; he had to tell the truth, and say that he was lying, when he was really telling the truth, which would be a lie.
He did say he was lying because he said his nose was going to grow, and even though he said he was lying, he was actually telling the truth; which means he was lying about lying, or lying about not telling the truth.
His nose did grow, and he did tell the truth, but he said he was lying when he was telling the truth, which was the lie that made his nose grow.
Since his nose didn't grow after he told the truth, but after he lied about not telling the truth; the paradox doesn't exist.
That second answer actually works for both scenarios, where as the first answer only works for the first scenario, so I suppose you can say the second answer is the correct one. Did you answer this riddle correctly?
YES NO
The Weight Of A Melon Riddle
Hint: We are to determine X the total mass of melon after the drying.
The Dry weight, DW is 1lb both before and after the drying.
The New Water weight, WNW is clearly X - DW or X - 1
A Fortune Cookie Riddle
A man says that every time he has gotten a fortune cookie his lucky numbers have always been the same, how is this possible???
Hint:
3 Cuts Riddle
Hint:
Solution 1: Use two cuts to divide the cake into four equal pieces (quarters). For the third cut, cut the cake in half, horizontally. Some pieces may not have any icing, but their size will be equal.
Solution 2: As in the first solution, use two cuts to divide the cake into four equal pieces (quarters). Then, stack the four pieces on top of each other and use a third cut to cut all four pieces in two. Did you answer this riddle correctly?
YES NO
Solution 2: As in the first solution, use two cuts to divide the cake into four equal pieces (quarters). Then, stack the four pieces on top of each other and use a third cut to cut all four pieces in two. Did you answer this riddle correctly?
YES NO
Coconut Sentence Riddle
Hint: Listen closely...
This.
If 'this' is a coconut, and 'that' is a coconut, then 'is' 'this' a coconut. Did you answer this riddle correctly?
YES NO
If 'this' is a coconut, and 'that' is a coconut, then 'is' 'this' a coconut. Did you answer this riddle correctly?
YES NO
Up A Drainpipe Riddle
Hint:
99 Points Riddle
While out bowling with his friends, a man managed to throw eight strikes (all ten pins knocked down in a single throw) and not a single gutter ball during the entire game. To his amazement, his final score was only 99 points! Assuming there were no penalties or fouls, can you come up with a ten frame scorecard with eight strikes and a final score of only 99 points?
Hint: If you knock down a single pin, for example at the far left of the back row, then repeat the same identical shot on your second throw, you'll score 0 points for your second throw (because there's no pin there anymore), but it's not a gutter ball as the s
Just to reiterate the hint, if you knock down a single pin, for example at the far left of the back row, then repeat the same identical shot on your second throw, you'll score 0 points for your second throw (because there's no pin there anymore), but it's not a gutter ball as the shot did not enter the gutter. Did you answer this riddle correctly?
YES NO
YES NO
Elevator Accident Riddle
Im in an elevator with two other people. When it reaches the first floor, one person gets out and six get in. When it reaches the second floor, three people get out and twelve get in. At the third floor, five leave and nine enter. It rises to the fourth floor, one person gets on and the doors close. Suddenly, the elevator cable snaps and the car smashes to the ground. No one survives the fall, yet Im alive and know exactly how many people go on and off the elevator at every floor. How is this possible?
Hint:
I got off at the first floor. Im a security guard and knew how many people got on and off the elevator by watching the surveillance footage. Did you answer this riddle correctly?
YES NO
YES NO
Crossing The Desert Riddle
A camel driver has to cross the desert and get to the Nile River to transport his merchandise. It takes six weeks to cross the desert and get to the Nile River. He can only carry four weeks of food for himself and his camel at any time because the camel also has to carry his merchandise. If he can not get help from anyone else or get anymore camels, and there is an unlimited supply of food where he is at, how can he cross the desert and get to the Nile River?
Hint:
He takes four weeks of food and leaves two weeks of food supplies in the one week mark and goes back with the one week of food supply left. Then he goes back with four weeks of food and picks up one week of food supplies from the one week mark giving him four again in total, then he leaves two weeks of supply in the two week mark and goes back to the one week mark and picks up the one week food supply to go back. Then he leaves with the four weeks of food supply and goes to the two week mark and picks up the two week food supplies that were there giving him four weeks of food again, then he goes to the Nile River with the four weeks supply of food. Did you answer this riddle correctly?
YES NO
YES NO
Under The Cup Riddle
You decide to play a game with your friend where your friend places a coin under one of three cups. Your friend would then switch the positions of two of the cups several times so that the coin under one of the cups moves with the cup it is under. You would then select the cup that you think the coin is under. If you won, you would receive the coin, but if you lost, you would have to pay.
As the game starts, you realise that you are really tired, and you don't focus very well on the moving of the cups. When your friend stops moving the cups and asks you where the coin is, you only remember a few things:
He put the coin in the rightmost cup at the start.
He switched two of the cups 3 times.
The first time he switched two of the cups, the rightmost one was switched with another.
The second time he switched two of the cups, the rightmost one was not touched.
The third and last time he switched two of the cups, the rightmost one was switched with another.
You don't want to end up paying your friend, so, using your head, you try to work out which cup is most likely to hold the coin, using the information you remember.
Which cup is most likely to hold the coin?
As the game starts, you realise that you are really tired, and you don't focus very well on the moving of the cups. When your friend stops moving the cups and asks you where the coin is, you only remember a few things:
He put the coin in the rightmost cup at the start.
He switched two of the cups 3 times.
The first time he switched two of the cups, the rightmost one was switched with another.
The second time he switched two of the cups, the rightmost one was not touched.
The third and last time he switched two of the cups, the rightmost one was switched with another.
You don't want to end up paying your friend, so, using your head, you try to work out which cup is most likely to hold the coin, using the information you remember.
Which cup is most likely to hold the coin?
Hint: Write down the possibilities. Remember that there are only three cups, so if the rightmost cup wasn't touched...
The rightmost cup.
The rightmost cup has a half chance of holding the coin, and the other cups have a quarter chance.
Pretend that Os represent cups, and Q represents the cup with the coin.
The game starts like this:
OOQ
Then your friend switches the rightmost cup with another, giving two possibilities, with equal chance:
OQO
QOO
Your friend then moves the cups again, but doesn't touch the rightmost cup. The only switch possible is with the leftmost cup and the middle cup. This gives two possibilities with equal chance:
QOO
OQO
Lastly, your friend switches the rightmost cup with another cup. If the first possibility shown above was true, there would be two possibilities, with equal chance:
OOQ
QOO
If the second possibility shown above (In the second switch) was true, there would be two possibilities with equal chance:
OOQ
OQO
This means there are four possibilities altogether, with equal chance:
OOQ
QOO
OOQ
OQO
This means each possibility equals to a quarter chance, and because there are two possibilities with the rightmost cup having the coin, there is a half chance that the coin is there. Did you answer this riddle correctly?
YES NO
The rightmost cup has a half chance of holding the coin, and the other cups have a quarter chance.
Pretend that Os represent cups, and Q represents the cup with the coin.
The game starts like this:
OOQ
Then your friend switches the rightmost cup with another, giving two possibilities, with equal chance:
OQO
QOO
Your friend then moves the cups again, but doesn't touch the rightmost cup. The only switch possible is with the leftmost cup and the middle cup. This gives two possibilities with equal chance:
QOO
OQO
Lastly, your friend switches the rightmost cup with another cup. If the first possibility shown above was true, there would be two possibilities, with equal chance:
OOQ
QOO
If the second possibility shown above (In the second switch) was true, there would be two possibilities with equal chance:
OOQ
OQO
This means there are four possibilities altogether, with equal chance:
OOQ
QOO
OOQ
OQO
This means each possibility equals to a quarter chance, and because there are two possibilities with the rightmost cup having the coin, there is a half chance that the coin is there. Did you answer this riddle correctly?
YES NO
100 Blank Cards Riddle
Someone offers you the following deal:
There is a deck of 100 initially blank cards. The dealer is allowed to write ANY positive integer, one per card, leaving none blank. You are then asked to turn over as many cards as you wish. If the last card you turn over is the highest in the deck, you win; otherwise, you lose.
Winning grants you $50, and losing costs you only the $10 you paid to play.
Would you accept this challenge?
There is a deck of 100 initially blank cards. The dealer is allowed to write ANY positive integer, one per card, leaving none blank. You are then asked to turn over as many cards as you wish. If the last card you turn over is the highest in the deck, you win; otherwise, you lose.
Winning grants you $50, and losing costs you only the $10 you paid to play.
Would you accept this challenge?
Hint: Perhaps thinking in terms of one deck is the wrong approach.
Yes!
A sample strategy:
Divide the deck in half and turn over all lower 50 cards, setting aside the highest number you find. Then turn over the other 50 cards, one by one, until you reach a number that is higher than the card you set aside: this is your chosen "high card."
Now, there is a 50% chance that the highest card is contained in the top 50 cards (it is or it isn't), and a 50% chance that the second-highest card is contained in the lower 50. Combining the probabilities, you have a 25% chance of constructing the above situation (in which you win every time).
This means that you'll lose three out of four games, but for every four games played, you pay $40 while you win one game and $50. Your net profit every four games is $10.
Obviously, you have to have at least $40 to start in order to apply this strategy effectively. Did you answer this riddle correctly?
YES NO
A sample strategy:
Divide the deck in half and turn over all lower 50 cards, setting aside the highest number you find. Then turn over the other 50 cards, one by one, until you reach a number that is higher than the card you set aside: this is your chosen "high card."
Now, there is a 50% chance that the highest card is contained in the top 50 cards (it is or it isn't), and a 50% chance that the second-highest card is contained in the lower 50. Combining the probabilities, you have a 25% chance of constructing the above situation (in which you win every time).
This means that you'll lose three out of four games, but for every four games played, you pay $40 while you win one game and $50. Your net profit every four games is $10.
Obviously, you have to have at least $40 to start in order to apply this strategy effectively. Did you answer this riddle correctly?
YES NO
100 Lbs Riddle
Hint:
Five Potatoes Riddle
A mother has six children and five potatoes. How can she feed each an equal amount of potatoes? Do not use fractions.
Hint:
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