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:
I Get Stronger Riddle
I can help you have some fun,
Sometimes I get stronger from the sun,
If you never give me a break,
You will find I never wake,
I am optimistic on one side,
I can be short, fat, tall or wide,
Rectangle and cylinder are two of my shapes,
And I can even help you make video tapes,
Sometimes you must wait for me to get ready,
Just hold on for a few hours and be steady,
I can help you get around the mall,
Or help you make a telephone call.
What am I?
Sometimes I get stronger from the sun,
If you never give me a break,
You will find I never wake,
I am optimistic on one side,
I can be short, fat, tall or wide,
Rectangle and cylinder are two of my shapes,
And I can even help you make video tapes,
Sometimes you must wait for me to get ready,
Just hold on for a few hours and be steady,
I can help you get around the mall,
Or help you make a telephone call.
What am I?
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:
Comes To Bedsides Riddle
He comes to bedsides, icy bridges,
battlefronts, and crumbling ridges.
When he comes, he comes alone,
taps a shoulder, then is gone.
battlefronts, and crumbling ridges.
When he comes, he comes alone,
taps a shoulder, then is gone.
Hint:
The Card Trick Riddle
A couple had to take shelter in a hotel for they could not proceed their journey in the rain. Having nothing to do at all, they started playing cards. Suddenly there was a short circuit and the lights went off. The husband inverted the position of 15 cards in the deck (52 cards normal deck) and shuffled the deck.
Now he asked his wife to divide the deck into two different piles which may not be equal but both of them should have equal number of cards facing up. There was no source of light in the room and the wife was unable to see the cards.
For a certain amount of time, she thought and then divided the cards in two piles. To the husbands astonishment, both of the piles had equal number of cards facing up.
How did she do it?
Now he asked his wife to divide the deck into two different piles which may not be equal but both of them should have equal number of cards facing up. There was no source of light in the room and the wife was unable to see the cards.
For a certain amount of time, she thought and then divided the cards in two piles. To the husbands astonishment, both of the piles had equal number of cards facing up.
How did she do it?
Hint:
The answer is very simple. All she had to do is take the fifteen cards from the top and reverse them. This would make another pile out of that and there will be two piles - one of 15 cards and one of 37 cards. Also both of them will have the same number of inverted cards.
Just think about it and if the mathematical explanation will help you understand better, here it is.
Assume that there were p inverted cards initially in the top 15 cards. Then the remaining 37 cards will hold 15-p inverted cards.
Now when she reverses the 15 cards on the top, the number of inverted cards will become 15-p and thus the number of inverted cards in both of the piles will become same. Did you answer this riddle correctly?
YES NO
Just think about it and if the mathematical explanation will help you understand better, here it is.
Assume that there were p inverted cards initially in the top 15 cards. Then the remaining 37 cards will hold 15-p inverted cards.
Now when she reverses the 15 cards on the top, the number of inverted cards will become 15-p and thus the number of inverted cards in both of the piles will become same. Did you answer this riddle correctly?
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:
A Useful Tool Riddle
Riddle me this
I'm white, and used for cutting and grinding. When I'm damaged, humans usually remove or fill me. For most animals I am a useful tool. What am I?
I'm white, and used for cutting and grinding. When I'm damaged, humans usually remove or fill me. For most animals I am a useful tool. What am I?
Hint:
Secretes You Can Keep Riddle
Riddle me this
You write on me and secrets I can keep. In places never seen. I spin like a top. Though stiff as a board, I'm often described like a mop. What am I?
You write on me and secrets I can keep. In places never seen. I spin like a top. Though stiff as a board, I'm often described like a mop. What am I?
Hint:
Running But No Walking Riddle
Hint:
Gone Too Fast Riddle
Riddle me this
Never ahead, ever behind, yet flying swiftly past; for a child, I last forever; for an adult, I'm gone too fast. What am I?
Never ahead, ever behind, yet flying swiftly past; for a child, I last forever; for an adult, I'm gone too fast. What am I?
Hint:
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