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
Prohibited Chess Riddle
Hint:
5 Houses Riddle
Here's more information:
An Englishman resides in a red house.
The Dane drinks tea.
Dogs are kept by the Swede.
The green house is left to the white house.
The occupant of the green house drinks coffee.
The birds are kept by the Pall Mall smoker.
The horse keeper and the Dunhill smoker live next to each other.
The German smokes Prince.
The Norwegian lives right next to the blue house.
The blend smoker's neighbor drinks water.
Hint:
Wrong Way Riddle
A truck driver is going opposite traffic on a one-way street. A police officer sees him but doesn't stop him. Why didn't the police officer stop him?
Hint:
This House Holds Rooms Riddle
This house holds rooms, one score and six, that shelter a vast mob.
It lets lions lie down with the lambs, Yet makes both shun the slob.
None now will nestle with nicks and nates, While reams room near the rear.
Though you and I have separate rooms. Both our bottles brim with beer. The king and queen can never mate (Though hands and hearts hobnob). Because their rooms are separate. If this jail does its job. What house is this that rules thus
Forcing faith to fend with fear? The answer to this riddle lies, with dead and dying here.
It lets lions lie down with the lambs, Yet makes both shun the slob.
None now will nestle with nicks and nates, While reams room near the rear.
Though you and I have separate rooms. Both our bottles brim with beer. The king and queen can never mate (Though hands and hearts hobnob). Because their rooms are separate. If this jail does its job. What house is this that rules thus
Forcing faith to fend with fear? The answer to this riddle lies, with dead and dying here.
Hint:
Over The Head Riddle
Hint:
The Robbery On The Third Floor Riddle
My wife and I took a much-needed holiday in England. It's a long flight from New York to London. We checked into a nice hotel. After a long day of sightseeing we just collapsed into bed. Just a few minutes ago, we were woken up by some noises outside. I looked out the window and the police were everywhere. They yelled up to me that there was a robbery and a murderer on the second floor. I'm on the third floor, and I can see and I can see that the cops have the stairs and elevators locked down. The murderer can't get up to our floor, so we're in no danger. My wife and I are tired, so we're going back to bed. I really hope they catch the guy.
Why did the police yell to the guy if he was on the 3rd floor?
Why did the police yell to the guy if he was on the 3rd floor?
Hint:
America and England have different ways of numbering floors. In America, it goes 1st floor, 2nd floor, 3rd floor. In England, it goes ground floor, 1st floor, 2nd floor. Did you answer this riddle correctly?
YES NO
YES NO
A Walk In The Desert Riddle
Four men walk into the desert. Suddenly all four are simultaneously knocked out. They awake buried to their heads in the sand unable to look anywhere but straight ahead. They are positioned so that each man sees another's head before him. However between the first and second man there is a separating wall.
So the first man sees only desert. The second man sees only wall. The third man sees another's head and a wall. The fourth man sees two heads and a wall. On top of each mans head is a hat. The underside of each cap is black, but the outside of each cap is either blue or white. Before any of the men can speak, their captors tell them if they speak, they die. However, if any of them can guess the color of their cap on the first try they go free. The captors tell them that there are two blue caps and two white caps.
Being an omniscient observer of the situation, we know that the order of the caps are: blue, white, blue, white. So knowing the perspective of each man in the sand, and that they can only see the color of caps/wall/desert in front of them, which of the four men knows for certain the color of his own cap. More importantly: why?
So the first man sees only desert. The second man sees only wall. The third man sees another's head and a wall. The fourth man sees two heads and a wall. On top of each mans head is a hat. The underside of each cap is black, but the outside of each cap is either blue or white. Before any of the men can speak, their captors tell them if they speak, they die. However, if any of them can guess the color of their cap on the first try they go free. The captors tell them that there are two blue caps and two white caps.
Being an omniscient observer of the situation, we know that the order of the caps are: blue, white, blue, white. So knowing the perspective of each man in the sand, and that they can only see the color of caps/wall/desert in front of them, which of the four men knows for certain the color of his own cap. More importantly: why?
Hint:
The third man. This is because he knows there are only two of each color cap. If the man behind him (the fourth man) saw two caps that were the same color in front of him, he would know that his own must be the opposite. However, because the caps alternate in color. The fourth man has only a 50% chance of getting his hat color correct, so therefore he stays quiet. The third man realizes that the fourth man is quiet because he must not see two caps of the same color in front of him, otherwise the fourth man would say the opposite of the caps in front of him. Therefore, the third man presumes his own cap must be the opposite of the mans in front of him, and his presumption is correct. Under this same logic, after the third man speaks his color hat, the second man, even though he sees only wall, would be the next to go free, because he knows his cap must be the opposite of whichever color the third mans cap was. Did you answer this riddle correctly?
YES NO
YES NO
150 Pens Riddle
Rihanna brought home 150 pens but while packing them, she misplaced some of them. When her brother asked how many she had misplaced, she told him:
If you count in pairs, one will remain
If you count in a group of three, two will remain
If you count in a group of four, three will remain
If you count in a group of five, four will remain
If you count in a group of six, five will remain
If you count in a group of seven, nothing will remain.
How many pens do you think has she misplaced ?
If you count in pairs, one will remain
If you count in a group of three, two will remain
If you count in a group of four, three will remain
If you count in a group of five, four will remain
If you count in a group of six, five will remain
If you count in a group of seven, nothing will remain.
How many pens do you think has she misplaced ?
Hint:
A Friendly Brain Riddle
Hint:
The Avid Birdwatcher Riddle
Hint:
The birdwatcher was flying in a plane. The bird got stuck in the planes engine and made the plane crash. Did you answer this riddle correctly?
YES NO
YES NO
Heavy Weight Riddle
Hint:
Hidden More Than Seen Riddle
Hint:
Driving Men Mad Riddle
Hint:
The Letter E Riddle
Riddle me this
I start with the letter e, I end with the letter e. I contain only one letter, Yet I am not the letter e! What am I?
I start with the letter e, I end with the letter e. I contain only one letter, Yet I am not the letter e! What am I?
Hint:
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