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Riddle:

There are 100 light bulbs lined up in a row in a long room. Each bulb has its own switch and is currently switched off. The room has an entry door and an exit door. There are 100 people lined up outside the entry door. Each bulb is numbered consecutively from 1 to 100. So is each person. Person No. 1 enters the room, switches on every bulb, and exits. Person No. 2 enters and flips the switch on every second bulb (turning off bulbs 2, 4, 6, ...). Person No. 3 enters and flips the switch on every third bulb (changing the state on bulbs 3, 6, 9, ...). This continues until all 100 people have passed through the room. What is the final state of bulb No. 64? And how many of the light bulbs are illuminated after the 100th person has passed through the room?

Answer:

First think who will operate each bulb, obviously person #2 will do all the even numbers, and say person #10 will operate all the bulbs that end in a zero. So who would operate for example bulb 48: Persons numbered: 1 & 48, 2 & 24, 3 & 16, 4 & 12, 6 & 8 ........ That is all the factors (numbers by which 48 is divisible) will be in pairs. This means that for every person who switches a bulb on there will be someone to switch it off. This willl result in the bulb being back at it's original state. So why aren't all the bulbs off? Think of bulb 36:- The factors are: 1 & 36, 2 & 13, 6 & 6 Well in this case whilst all the factors are in pairs the number 6 is paired with it's self. Clearly the sixth person will only flick the bulb once and so the pairs don't cancel. This is true of all the square numbers. There are 10 square numbers between 1 and 100 (1, 4, 9, 16, 25, 36, 49, 64, 81 & 100) hence 10 bulbs remain on.

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Riddle:

A great banquet was prepared for a Roman emperor and his courtiers. 22 Dormice, 40 Larks' Tongues, 30 Flamingos and 40 Roast Parrots were served.

How many portions of Boiled Ostrich were served?

Answer:

42. Each vowel is worth 2 and each consonant 4, so Dormice gives 22, ect.

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Riddle:

Marco and Bob have been the best friends ever since they were little kids. They are also very competitive. Throughout the years they have challenged each other to do both physical and mental challenges. And they completed the challenge. But one day Marco thought of something to challenge Bob to do - something he could start but never finish. The average man could do it and so could Mark and they were both the same sex and the same size. It is a physical challenge. Can you figure out what it was?

Answer:

Marco challenged Bob to get a tan, but he couldn't...Bob is an albino.

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Riddle:

The word FACETIOUSLY
contains the six vowels, A-E-I-O-U and Y,
in their alphabetical order.
Can you find another English word that does the same?

Answer:

The word is abstemiously. There may be others.

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Riddle:

Two cars were involved in an accident in the center of town. The man who was driving a little green car, had overtaken a big black car. The driver had misjudged the distance between him and the on-coming traffic and had to swerve back in, causing the black car to swerve and crash into a shop window. When the occupants of the cars were examined everyone in the green car was okay, but in the black car was one dead man. However, the driver of the green car was not charged with manslaughter, why was this so?

Answer:

The black car was a hearse and was on its way to a funeral.

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Riddle:

It's always 1 to 6,
it's always 15 to 20,
it's always 5,
but it's never 21,
unless it's flying.

What is it?

Answer:

The answer is: a dice. An explanation: "It's always 1 to 6": the numbers on the faces of the dice, "it's always 15 to 20": the sum of the exposed faces when the dice comes to rest after being thrown, "it's always 5": the number of exposed faces when the dice is at rest, "but it's never 21": the sum of the exposed faces is never 21 when the dice is at rest, "unless it's flying": the sum of all exposed faces when the dice is flying is 21 (1 + 2 + 3 + 4 + 5 + 6).

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Riddle:

A boy leaves home in the morning to go to school. At the moment he leaves the house he looks at the clock in the mirror. The clock has no number indication and for this reason the boy makes a mistake in interpreting the time (mirror-image). Just assuming the clock must be out of order, the boy cycles to school, where he arrives after twenty minutes. At that moment the clock at school shows a time that is two and a half hours later than the time that the boy saw on the clock at home.

Answer:

The difference between the real time and the time of the mirror image is two hours and ten minutes (two and a half hours, minus the twenty minutes of cycling). Therefore, the original time on the clock at home that morning could only have been five minutes past seven: The difference between these clocks is exactly 2 hours and ten minutes (note that also five minutes past one can be mirrored in a similar way, but this is not in the morning!). Conclusion: The boy reaches school at five minutes past seven plus twenty minutes of cycling, which is twenty-five minutes past seven!...

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Riddle:

How can this be true? Have a look at the picture. All the lines are straight, the shapes that make up the top picture are the same as the ones in the bottom picture so where does the gap come from?

Answer:

The green triangle has dimensions 2 x 5 and gradient 2 / 5 = 0.4
The red triangle has dimensions 3 x 8 and gradient 3 / 8 = 0.375
Hence the gradient of the green triangle is greater than that of the red triangle.

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Riddle:

An item is made from lead blanks in a lathe shop. Each blank suffices for 1 item. Lead shavings accumulated for making 6 items can be melted and made into a blank. How many items can be made from 36 blanks?

Answer:

From 36 blanks there are 36 items made. The lead shavings are enough to make 6 blanks. Which make 6 more items. But don't stop here. The new shavings are good for 1 more item. Total: 43.

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Riddle:

I run, it runs, I stop, it runs

What it it? 

Answer:

My watch.

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