OH RIDDLES WITH ANSWERS TO SOLVE - PUZZLES & BRAIN TEASERS

A map Did you answer this riddle correctly?
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Those that remain behind must have written {1,4,6,8,9} and from this only {1,9} are odd. The probability of an odd number is thus 2/5.
Expected number of odds is 2/5 * 90 = 36 Did you answer this riddle correctly?
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The answer is to let your friend go first. This puzzle is based on an old game/scam called Penny Ante. No matter what you picked, your friend would be able to come up with a combination which would be more likely to beat yours. For example, if you were to choose HHH, then unless HHH was the first combination to come up you would eventually lose since as soon as a Tails came up, the combination THH would inevitably come up before HHH. The basic formula you can use for working out which combination you should choose is as follows. Simply take his combination (eg. HHT) take the last term in his combination, put it at the front (in this case making THH) and your combination will be more likely to come up first. Try it on your friends! Did you answer this riddle correctly?
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1/10

For a group of n friends, there are n! (n factorial) ways to draw the names out of the hat. Since a circle does not have a beginning and end, choose one person as the beginning and end of the circle. There are now (n-1)! ways to distribute the remaining people around the circle. Thus the probability of forming a single circle is

(n-1)! / n!

Since n! = (n-1)! * n (for n > 1), this can be rewritten as

(n-1)! / (n*(n-1)!)

Factoring out the (n-1)! from the numerator and denominator leaves

1/n

as the probability. Did you answer this riddle correctly?
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1/3

This is a famous question in understanding conditional probability, which simply means that given some information you might be able to get a better estimate.

The following are possible combinations of two children that form a sample space in any earthly family:

Boy - Girl
Girl - Boy
Boy - Boy
Girl - Girl

Since we know one of the children is a boy, we will drop the girl-girl possibility from the sample space.
This leaves only three possibilities, one of which is two boys. Hence the probability is 1/3 Did you answer this riddle correctly?
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He should shoot at the ground.

If Mr. Black shoots the ground, it is Mr. Gray's turn. Mr. Gray would rather shoot at Mr. White than Mr. Black, because he is better. If Mr. Gray kills Mr. White, it is just Mr. Black and Mr. Gray left, giving Mr. Black a fair chance of winning. If Mr. Gray does not kill Mr. White, it is Mr. White's turn. He would rather shoot at Mr. Gray and will definitely kill him. Even though it is now Mr. Black against Mr. White, Mr. Black has a better chance of winning than before. Did you answer this riddle correctly?
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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?
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We’ll use A to represent the first cowboy and B for the second cowboy.

A + 1 = 2A, so A = 1.
A + 1 = B – 1, so B = 3. Did you answer this riddle correctly?
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To the library Did you answer this riddle correctly?
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It was a coconut Did you answer this riddle correctly?
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Im a daisy Did you answer this riddle correctly?
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She reasoned that if the guy appeared at her mother's funeral, then he might appear another family funeral.

If you answered this correctly, you think like a psychopath. This was a test by a famous American psychologist used to test if one has the same mentality as a killer. Many arrested serial killers took part in this test and answered correctly. Did you answer this riddle correctly?
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By its handle! Did you answer this riddle correctly?
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I'm Batman! Did you answer this riddle correctly?
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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?
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