Lakes And Boats Riddle
There is a lake with shores A and B. Two motorboats M and N are standing on the opposite sides (A and B respectively). M leaves A and N leaves B and start moving with constant speeds. They meet for the first time 500 yards away from A. After touching the shores, they return back to the previous shore point without taking any break. This time they meet at 300 yards away from B.
Can you determine how wide the lake is? What is the relation between the speeds of boats?
Can you determine how wide the lake is? What is the relation between the speeds of boats?
Hint:
When the boats meet for the first time, they have sailed a combined distance that is equal to one length of the lake. When they meet the second time, they have sailed 3 lengths. The elapsed time and the distance for each is three times.
When they meet for the second time, the boat M has sailed 500 x 3 = 1500 yards. Now, this is 300 yards longer than the length of the lake, it must be 1200 yards wide.
The ration between the speed of boat M and boat N is equal to the ratio of the distance that they have sailed before they meet the first time. Did you answer this riddle correctly?
YES NO
When they meet for the second time, the boat M has sailed 500 x 3 = 1500 yards. Now, this is 300 yards longer than the length of the lake, it must be 1200 yards wide.
The ration between the speed of boat M and boat N is equal to the ratio of the distance that they have sailed before they meet the first time. Did you answer this riddle correctly?
YES NO
Who Is The Engineer Riddle
A train goes between Chicago and New York. The brakeman, the fireman and the engineer are named Smith, Jones and Brown. (The names are not necessarily in order). There are also three passengers named Mr. Smith, Mr. Jones and Mr. Brown. Mr. Brown lives in New York. The brakeman lives halfway between New York and Chicago. Mr. Jones earns exactly $20,000 per year. Smith beat the fireman at their last game of golf. The passenger who lives in Chicago has the same name as the brakeman. The brakeman's next door neighbor is a passenger on this train and earns exactly three times as much as the brakeman. What is the name of the engineer?
Hint:
Determine the known facts. Also notice that the passengers are noted with the title Mr., where as the brakeman, engineer and fireman are identified by their last names only. 1. Mr Brown Lives in New York City 2. The brakeman lives midway between NY and Chicago 3. Mr. Jones earns exactly $20K per year 4. Smith beat the fireman at their last game of golf. 5. The brakeman's next-door neighbor, who is a passenger, earns exactly three times the brakeman's salary. 6. The passenger who lives in Chicago has the same name as the brakeman. According to #1 and #2, the brakeman's neighbor cannot be Mr. Brown. According to #5, the brakeman's neighbor also cannot be Mr. Jones, because $20,000 is not evenly divisible by three. This leaves Mr. Smith as the next door neighbor to the brakeman. Mr. Smith lives halfway between New York and Chicago (#2) as does the brakeman. Since Mr. Brown lives in New York, by process of elimination, it is now known that Mr. Jones lives in Chicago. According to statement #6, this means that the brakeman is named Jones. According to statement #4, the fireman cannot be Smith, so the fireman must be must be Brown, which leaves Smith as the engineer. Did you answer this riddle correctly?
YES NO
YES NO
The 100 Seat Airplane
People are waiting in line to board a 100-seat airplane. Steve is the first person in the line. He gets on the plane but suddenly can't remember what his seat number is, so he picks a seat at random. After that, each person who gets on the plane sits in their assigned seat if it's available, otherwise they will choose an open seat at random to sit in.
The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?
The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?
Hint: You don't need to use complex math to solve this riddle. Consider these two questions:
What happens if somebody sits in your seat?
What happens if somebody sits in Steve's assigned seat?
The correct answer is 1/2.
The chase that the first person in line takes your seat is equal to the chance that he takes his own seat. If he takes his own seat initially then you have a 100% chance of sitting in your seat, if he takes your seat you have a 0 percent chance. Now after the first person has picked a seat, the second person will enter the plan and, if the first person has sat in his seat, he will pick randomly, and again, the chance that he picks your seat is equal to the chance he picks someone your seat. The motion will continue until someone sits in the first persons seat, at this point the remaining people standing in line which each be able to sit in their own seats. Well how does that probability look in equation form? (2/100) * 50% + (98/100) * ( (2/98) * 50% + (96/98) * ( (2/96) * (50%) +... (2/2) * (50%) ) ) This expansion reduces to 1/2.
An easy way to see this is trying the problem with a 3 or 4 person scenario (pretend its a car). Both scenarios have probabilities of 1/2. Did you answer this riddle correctly?
YES NO
The chase that the first person in line takes your seat is equal to the chance that he takes his own seat. If he takes his own seat initially then you have a 100% chance of sitting in your seat, if he takes your seat you have a 0 percent chance. Now after the first person has picked a seat, the second person will enter the plan and, if the first person has sat in his seat, he will pick randomly, and again, the chance that he picks your seat is equal to the chance he picks someone your seat. The motion will continue until someone sits in the first persons seat, at this point the remaining people standing in line which each be able to sit in their own seats. Well how does that probability look in equation form? (2/100) * 50% + (98/100) * ( (2/98) * 50% + (96/98) * ( (2/96) * (50%) +... (2/2) * (50%) ) ) This expansion reduces to 1/2.
An easy way to see this is trying the problem with a 3 or 4 person scenario (pretend its a car). Both scenarios have probabilities of 1/2. Did you answer this riddle correctly?
YES NO
A Farmer Crossing A River
A farmer has to get a sack of corn, a chicken, and a fox across a river. The farmer is only able to bring one of the above items along with him at a time. The only problem is if he leaves the fox alone with the chicken, the fox will eat the chicken, and if he leaves the chicken along the corn sack, then the chicken will eat the corn sack. How does the farmer get all 3 items across safely?
Hint: The farmer can bring items across the river both ways.The farmer brings the chicken across the river first.
The farmer brings the chicken across. Goes back and brings the fox across, and brings the chicken back with him to the other side of the river and drops off the chicken, then he goes and brings the corn sack across, and finally he goes back for the chicken and brings it across. Did you answer this riddle correctly?
YES NO
YES NO
Coffee Diner Riddle
A man walks into a diner and sits down. There's a new waitress working that he's never seen before. When she comes to his table to take his order, he says "Just a cup of coffee please." A few minutes later the waitress brings the man his coffee and heads back to the kitchen. A short while later, the man notices that there is a fly in his coffee and calls the waitress back. He asks her nicely to bring him another cup. The waitress brings the man's cup of coffee back to the kitchen and returns a few moments later. "Here you are, I poured you a new cup of coffee, no fly this time" she says and hands him the cup. The waitress turns around and starts to head back to the kitchen. She only takes a few steps before she hears the man shout out "Hey, this is the same cup of coffee, all you did was remove the fly!"
Assuming the coffee was still hot, how did the man know it was the same cup of coffee?
Assuming the coffee was still hot, how did the man know it was the same cup of coffee?
Hint: A man walks into a diner and sits down. There's a new waitress working that he's never seen before. When she comes to his table to take his order, he says "Just a cup of coffee please." A few minutes later the waitress brings the man his coffee and heads
Because the coffee was sweet. The man had added sugar to his coffee before noticing the fly. When the waitress brought him the "new" cup of coffee, he took a sip (to check whether it was in fact a newly poured cup of coffee) and noticed that the coffee was "already" sweet. Did you answer this riddle correctly?
YES NO
YES NO
The Color On Top Riddle
When youre driving in a car
This color is on top
Of a set of traffic lights
It means that you should stop.
This color is..?
This color is on top
Of a set of traffic lights
It means that you should stop.
This color is..?
Hint:
The Color Of Many Foods Riddle
Many foods are this color
Like some types of cherries
Tomatoes and some peppers
As well as strawberries.
It is?
Like some types of cherries
Tomatoes and some peppers
As well as strawberries.
It is?
Hint:
The Color Of Snooker Riddle
This color is on the US flag
It's the shade of some apples
And if you ever play snooker
There are fifteen of these balls.
It's the shade of some apples
And if you ever play snooker
There are fifteen of these balls.
Hint:
The Color Of Love Riddle
Lipstick is this color
And ladybugs in part
And on Valentines Day
Some roses and a heart?
What could this color be?
And ladybugs in part
And on Valentines Day
Some roses and a heart?
What could this color be?
Hint:
The Bee And The Bikes Riddle
Two bikes are traveling toward each other at a constant speed of 10 mph. When the bike are 20 miles apart, a bee flies from the front wheel of one of the bikes toward the other bike at a constant speed of 25 mph. As soon as it reaches the front wheel of the other bike, it immediately turns around and flies at 25 mph toward the first bike. It continues this pattern until the two bikes smush the bee between the two front tires.
How far did the bee travel?
How far did the bee travel?
Hint:
25 miles.
The easiest way to think about this is to consider the time. The bikes will take 1 hour to touch, given that they start 20 miles apart and are each traveling toward each other at 10 mph.
Therefore the bee is buzzing back and forth at 25 mph for 1 hour. Did you answer this riddle correctly?
YES NO
The easiest way to think about this is to consider the time. The bikes will take 1 hour to touch, given that they start 20 miles apart and are each traveling toward each other at 10 mph.
Therefore the bee is buzzing back and forth at 25 mph for 1 hour. Did you answer this riddle correctly?
YES NO
The Longest Camping Trip Riddle
A group of campers have been on vacation so long, that they've forgotten the day of the week. The following conversation ensues.
Darryl: What's the day? I dont think it is Thursday, Friday or Saturday.
Tracy: Well that doesn't narrow it down much. Yesterday was Sunday.
Melissa: Yesterday wasn't Sunday, tomorrow is Sunday.
Ben: The day after tomorrow is Saturday.
Adrienne: The day before yesterday was Thursday.
Susie: Tomorrow is Saturday.
David: I know that the day after tomorrow is not Friday.
If only one person's statement is true, what day of the week is it?
Darryl: What's the day? I dont think it is Thursday, Friday or Saturday.
Tracy: Well that doesn't narrow it down much. Yesterday was Sunday.
Melissa: Yesterday wasn't Sunday, tomorrow is Sunday.
Ben: The day after tomorrow is Saturday.
Adrienne: The day before yesterday was Thursday.
Susie: Tomorrow is Saturday.
David: I know that the day after tomorrow is not Friday.
If only one person's statement is true, what day of the week is it?
Hint:
It is Wednesday. If it was any other day of the week, more than one statement would be true. To solve the riddle, evaluate each person's statement and write down what day it could be according to the statement. David's statement indicates it could be any day of the week except for Wednesday. When you list the days that it could be according to everyone's statement, it turns out Wednesday is the day mentioned only one time. Darryl: Sunday, Monday, Tuesday, or Wednesday Tracy: Monday Melissa: Saturday Ben: Thursday Adrienne: Saturday Susie: Friday David: Sunday, Monday, Tuesday, Thursday, Friday or Saturday Did you answer this riddle correctly?
YES NO
YES NO
Sam And Angela's Camping Trip
Sam and Angela were on a camping trip. When making dinner, they discovered that neither of them had brought a clock or a watch. Dinner required cooking for 45 minutes. All Sam could dig up was a couple of mosquito coils that would each burn for one hour. They didn't have any method to measure the coils in any way. Angela figured out a way to measure 45 minutes using the two coils (and fight off mosquitoes at the same time). How did she accomplish this task?
Hint:
Angela first lit one mosquito coil at both ends and then lit the other on only one side. The coil which had been lit on both ends finished burning in one-half hour. At that point the second mosquito coil had one-half hour left to burn. Angela lit the second coil at the other end, and it finished burning fifteen minutes later. (45 minutes total) Did you answer this riddle correctly?
YES NO
YES NO
Marrying The Princess Riddle
A king wants his daughter to marry the smartest of 3 extremely intelligent young princes, and so the king's wise men devised an intelligence test.
The princes are gathered into a room and seated, facing one another, and are shown 2 black hats and 3 white hats. They are blindfolded, and 1 hat is placed on each of their heads, with the remaining hats hidden in a different room.
The king tells them that the first prince to deduce the color of his hat without removing it or looking at it will marry his daughter. A wrong guess will mean death. The blindfolds are then removed.
You are one of the princes. You see 2 white hats on the other prince's heads. After some time you realize that the other prince's are unable to deduce the color of their hat, or are unwilling to guess. What color is your hat?
The princes are gathered into a room and seated, facing one another, and are shown 2 black hats and 3 white hats. They are blindfolded, and 1 hat is placed on each of their heads, with the remaining hats hidden in a different room.
The king tells them that the first prince to deduce the color of his hat without removing it or looking at it will marry his daughter. A wrong guess will mean death. The blindfolds are then removed.
You are one of the princes. You see 2 white hats on the other prince's heads. After some time you realize that the other prince's are unable to deduce the color of their hat, or are unwilling to guess. What color is your hat?
Hint: You know that your competitors are very intelligent and want nothing more than to marry the princess. You also know that the king is a man of his word, and he has said that the test is a fair test of intelligence and bravery.
Answer: White.
The king would not select two white hats and one black hat. This would mean two princes would see one black hat and one white hat. You would be at a disadvantage if you were the only prince wearing a black hat.
If you were wearing the black hat, it would not take long for one of the other princes to deduce he was wearing a white hat.
If an intelligent prince saw a white hat and a black hat, he would eventually realize that the king would never select two black hats and one white hat. Any prince seeing two black hats would instantly know he was wearing a white hat. Therefore if a prince can see one black hat, he can work out he is wearing white.
Therefore the only fair test is for all three princes to be wearing white hats. After waiting some time just to be sure, you can safely assert you are wearing a white hat. Did you answer this riddle correctly?
YES NO
The king would not select two white hats and one black hat. This would mean two princes would see one black hat and one white hat. You would be at a disadvantage if you were the only prince wearing a black hat.
If you were wearing the black hat, it would not take long for one of the other princes to deduce he was wearing a white hat.
If an intelligent prince saw a white hat and a black hat, he would eventually realize that the king would never select two black hats and one white hat. Any prince seeing two black hats would instantly know he was wearing a white hat. Therefore if a prince can see one black hat, he can work out he is wearing white.
Therefore the only fair test is for all three princes to be wearing white hats. After waiting some time just to be sure, you can safely assert you are wearing a white hat. Did you answer this riddle correctly?
YES NO
Refreshed And Full Of Energy
Discovered in Africa, I spread like a tide, to become a hot staple known the world wide. A necessity to some, a treasure to many, Im best enjoyed among pleasant company. Some like me hot and some like me cold. Some prefer mild, others only bold. Some take me straight, while some like to savor my essence to which has been added a flavor. So put down your cares and sit awhile with me; Ill send you back refreshed and full of energy. What am I?
Hint:
Losing A New York Bet
You are hanging around in NYC when a person approaches you.
"Leaving the bald people aside, I can bet a hundred bucks that there are two people living in NYC who have same number of hairs on their heads," he says to you.
You say that you will take the bet. After talking to the man for a couple of minutes, you realize that you have lost the bet.
What did the person say to you that proved his statement ?
"Leaving the bald people aside, I can bet a hundred bucks that there are two people living in NYC who have same number of hairs on their heads," he says to you.
You say that you will take the bet. After talking to the man for a couple of minutes, you realize that you have lost the bet.
What did the person say to you that proved his statement ?
Hint:
This problem can be best solved using the pigeonhole principle.
The argument will go like this:
Assume that all the non-bald people in NYC have different number of hairs on their head. The population is about 9 million and let us assume that there are 8 million among them who are not bald.
Now, those 8 million people need to have different number of hairs. On an average, people have just 100, 000 hairs on their head. If we keep on assuming that there is someone with just one hair, someone with two, someone with three and so on, there will be 7, 900, 00 other people left who will have more than 100, 000 hairs on their head and need different number of hairs.
Now, as per this assumption, if we keep increasing one hair for each person, to make everybody hair different in numbers, we will come across someone with 8, 000, 000 hairs. But that is practically impossible (even 1, 000, 000 is impossible). Thus there must be two people who are having same number of hairs. Did you answer this riddle correctly?
YES NO
The argument will go like this:
Assume that all the non-bald people in NYC have different number of hairs on their head. The population is about 9 million and let us assume that there are 8 million among them who are not bald.
Now, those 8 million people need to have different number of hairs. On an average, people have just 100, 000 hairs on their head. If we keep on assuming that there is someone with just one hair, someone with two, someone with three and so on, there will be 7, 900, 00 other people left who will have more than 100, 000 hairs on their head and need different number of hairs.
Now, as per this assumption, if we keep increasing one hair for each person, to make everybody hair different in numbers, we will come across someone with 8, 000, 000 hairs. But that is practically impossible (even 1, 000, 000 is impossible). Thus there must be two people who are having same number of hairs. Did you answer this riddle correctly?
YES NO
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