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
As Long As Its Value Riddle
Hint:
Thirteen Hearts Riddle
Hint:
Less Than 100 Riddle
Find a number less than 100 that is increased by one-fifth of its value when its digits are reversed.
Hint:
Closest To The Sun Riddle
80 is my atomic number
And I have the symbol Hg
Im the planet closest to the sun
Which means my name is what?
And I have the symbol Hg
Im the planet closest to the sun
Which means my name is what?
Hint:
Making Ten Riddle
Hint:
Yes it is possible in Roman Numerals. In Roman Numerals,
9 = IX
10 = X
11 = XI
Thus by removing one from 9, you are getting 10 and by removing one from 11, you are getting 10 again. Did you answer this riddle correctly?
YES NO
9 = IX
10 = X
11 = XI
Thus by removing one from 9, you are getting 10 and by removing one from 11, you are getting 10 again. Did you answer this riddle correctly?
YES NO
52 Pickup Riddle
A pack of cards has 52 cards. You are blindfolded. Out of 52, 42 cards are facing down while 10 are facing up. You have been asked to divide this pack of cards into two decks - so that each deck contains an equal number of face up cards. Remember, you are blindfolded.
How will you do it?
How will you do it?
Hint:
Take 10 number of cards in a new deck and change their face direction. For example- You create a new deck of 10 cards and out of 10, 3 faces up in the new deck. So remaining 7 faces up are in the old deck. But hey! while creating the new deck you reversed the face direction of new cards. So actually the 3 cards which were facing up are actually face down in the new deck while 7 faces up. Did you answer this riddle correctly?
YES NO
YES NO
Folding Newspaper Riddle
Hint:
Only once. After that youre folding it into quarters, eights and so on. Did you answer this riddle correctly?
YES NO
YES NO
Four Days Of School Riddle
A student has missed an excessive number of days at school and thus the principal called him to his office and requested for an explanation.
The student said, There just isnt enough time for school. I need 8 hours of sleep a day, which adds up to about 122 days a year. Weekends off is 104 days a year. Summer vacation is about 60 days. If I spend about an hour on each meal, thats 3 hours a day or 45 days a year. I need at least 2 hours of exercise and relaxation time each day to stay physically and mentally fit, adding another 30 days.
Add all of that up and you get about 361 days. That only leaves 4 days for school.
The principal is confused, but cant figure out why. What is wrong with the students argument?
The student said, There just isnt enough time for school. I need 8 hours of sleep a day, which adds up to about 122 days a year. Weekends off is 104 days a year. Summer vacation is about 60 days. If I spend about an hour on each meal, thats 3 hours a day or 45 days a year. I need at least 2 hours of exercise and relaxation time each day to stay physically and mentally fit, adding another 30 days.
Add all of that up and you get about 361 days. That only leaves 4 days for school.
The principal is confused, but cant figure out why. What is wrong with the students argument?
Hint:
The student is double counting a lot of the days. A lot of the time spent sleeping, eating, and relaxing occurs during weekends and the summer. Weekends also occur during the summer, so all of these hours are getting counted several times.
And, school is not an all day affair. So the 4 days actually represents more days of school. If school is 6 hours per day, those four days represents 16 days of school. Did you answer this riddle correctly?
YES NO
And, school is not an all day affair. So the 4 days actually represents more days of school. If school is 6 hours per day, those four days represents 16 days of school. Did you answer this riddle correctly?
YES NO
Zebras And Ostriches In The Zoo
There are zebras and ostriches in this Zoo.
You count 80 heads and 200 legs.
Can you find the number of Zebras and the number of Ostriches in the Zoo?
You count 80 heads and 200 legs.
Can you find the number of Zebras and the number of Ostriches in the Zoo?
Hint:
The number of Ostriches = 60 & The number of Zebras = 20 Did you answer this riddle correctly?
YES NO
YES NO
Odd Number Becomes Even
Can you solve this classic number riddle before getting hung?
Hint: Spell the number out.
Roman Numeral IX Riddle
Hint:
Malcolm's Age Riddle
Malcolm is the number of weeks of his fathers age treated as days and his grandfathers age in months. All three of their ages add up to 120 years. How old is Malcolm, his father and his grandfather?
Hint:
Malcolm is 6.
The father is 42. 42 days = 6 weeks.
The grandfather is 72. 72 months = 6 years. Did you answer this riddle correctly?
YES NO
The father is 42. 42 days = 6 weeks.
The grandfather is 72. 72 months = 6 years. Did you answer this riddle correctly?
YES NO
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
21 Jars Riddle
You have 21 jars with you. Out of them, 7 are filled with water, 7 are half-full with water and 7 are empty. How will you distribute the jars among three people such that each one of them gets the equal number of jars and equal amount of water?
Hint:
Give 3 full, 1 half-full and 3 empty bottles to the first person.
Give 3 full, 1 half-full and 3 empty bottles to the second person.
Give 1 full, 5 half-full and 1 empty bottle to the third person. Did you answer this riddle correctly?
YES NO
Give 3 full, 1 half-full and 3 empty bottles to the second person.
Give 1 full, 5 half-full and 1 empty bottle to the third person. Did you answer this riddle correctly?
YES NO
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