Brain Teasers

ChrisZimbo

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May 22, 2004
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Currently South Africa, Hometown is Zimbabwe
Problem 1: (very very very easy)

U have 2 measuring pots, one is 3 liter and other is 5 liter.... Now you need to measure exactly 4 liter using these two pots.... how u would do that ???????? (mention the steps)

Problem 2: (very very easy)

Equally divide 24 liters of milk among 3 person (8 liter each)..... U only have 3 measuring pots/vessels of 5 liter, 11 liter and 13 liter (mention the steps)

Problem 3: (easy)

U are given 12 balls of identical weights, unfortunately one ball is defective (not equal in weight with others).... now u are given a scale without measuring weights..... can u detect the defective ball with only 3 measures of scale(mention the steps)

Problem 4: (not very easy)

U have 11 open boxes, 10 of them contains 10 balls each and each ball is 10 gram (total of 100 gram per box).... but one box have balls of 9 gram each (total of 90 grams) and u don't know which box.... now u are given a scale and measuring weights..... can u find the box containing lighter balls in just one meaurement ?????????

Problem 5:

your little sister just turned 10 and she wants her 10 candles arranged in her birthday cake in 5 rows of 4 each.. She won't have it in any other way !!!!!! is this posible ??? if so how ??? (some people may suggest the breaking of candles in half.. this is not allowed)

Problem 6:

In 1998 I was as old as the last two digits of my birth year... when I mention this interesting coincidence to my father , he surprised me by saying that the same appied to him too. how old was my father in 1998 ???????

Problem 7:

My grandfather was born in 1895. in 1995 we celebrated his birth centenary.. grandfather told us that although each of his birthdays was observed either by his parents, sons or grandsons but there were only 24 such occasions.. how was it possible ????

Problem 8: (easy)

Each candlestick is capable of glowing for an hour... remainders of 8 candlesticks can be used as one full candle..... How many maximum hours of light can be provided by a bunch of 64 candlesticks ?????

Problem 9:

Three meadows covered with grass of the same thickness and rate of growth.... the area of them are 2, 10 and 24 hectares respectively... First served to feed 12 oxen during 4 weeks.... Second served to feed 21 oxen during 9 weeks.. how many oxen can feed on the third meadow in the course of 18 weeks ?????

(this problem was not devised by Newton himself but is the product of folklore in mathematics)

Problem 10: (easy)

Express 1000 using the same digit exactly eight times... Basic arithmatic operations are permitted..... (1000= ....... + ,,,,,,,,, -''''''''''' + in this way)
 
U have 2 measuring pots, one is 3 liter and other is 5 liter.... Now you need to measure exactly 4 liter using these two pots.... how u would do that ????????

haha, straight out of Die Hard III. I know how it goes, but I don't feel like typin.
 
Problem 7:

My grandfather was born in 1895. in 1995 we celebrated his birth centenary.. grandfather told us that although each of his birthdays was observed either by his parents, sons or grandsons but there were only 24 such occasions.. how was it possible ????

the only answer i got to this was that he meant observed from heaven maybe. or observed from another aspect other than actually being there. I dont know.


Each candlestick is capable of glowing for an hour... remainders of 8 candlesticks can be used as one full candle..... How many maximum hours of light can be provided by a bunch of 64 candlesticks ?????

i believe its 72 hours.

thats all i think i can try to get right now
 
Problem 1: (very very very easy)

U have 2 measuring pots, one is 3 liter and other is 5 liter.... Now you need to measure exactly 4 liter using these two pots.... how u would do that ???????? (mention the steps)

fill the 5 to the top and pour it into the 3 until its full
so u have 2 and 3 litres. then dump the 3L pot, and put the 2L into the 3L pot. Fill up the 5L to the top and pour it in the 3L till its full (i.e 1L) then u have 4L in the 5L pot.

Problem 2: (very very easy)

Equally divide 24 liters of milk among 3 person (8 liter each)..... U only have 3 measuring pots/vessels of 5 liter, 11 liter and 13 liter (mention the steps)

is this asking 3 8L pots at the same time? cuz thats not possible. if not
Fill 13, then pour 5 into the 5L. Now there's 8L in the 13L. pour it into the 11L. give 8L to first person and repeat for other 3

Problem 3: (easy)

U are given 12 balls of identical weights, unfortunately one ball is defective (not equal in weight with others).... now u are given a scale without measuring weights..... can u detect the defective ball with only 3 measures of scale(mention the steps)
dont know. this has me stumped


Problem 4: (not very easy)

U have 11 open boxes, 10 of them contains 10 balls each and each ball is 10 gram (total of 100 gram per box).... but one box have balls of 9 gram each (total of 90 grams) and u don't know which box.... now u are given a scale and measuring weights..... can u find the box containing lighter balls in just one meaurement ?????????
dunno.. just count how many balls?

Problem 5:

your little sister just turned 10 and she wants her 10 candles arranged in her birthday cake in 5 rows of 4 each.. She won't have it in any other way !!!!!! is this posible ??? if so how ??? (some people may suggest the breaking of candles in half.. this is not allowed)

trick question. i don't have a little sister.


Problem 6:

In 1998 I was as old as the last two digits of my birth year... when I mention this interesting coincidence to my father , he surprised me by saying that the same appied to him too. how old was my father in 1998 ???????

49 (son)
and
99 (father)

Problem 7:

My grandfather was born in 1895. in 1995 we celebrated his birth centenary.. grandfather told us that although each of his birthdays was observed either by his parents, sons or grandsons but there were only 24 such occasions.. how was it possible ????

he's senile.


Problem 8: (easy)

Each candlestick is capable of glowing for an hour... remainders of 8 candlesticks can be used as one full candle..... How many maximum hours of light can be provided by a bunch of 64 candlesticks ?????
73


Problem 9:

Three meadows covered with grass of the same thickness and rate of growth.... the area of them are 2, 10 and 24 hectares respectively... First served to feed 12 oxen during 4 weeks.... Second served to feed 21 oxen during 9 weeks.. how many oxen can feed on the third meadow in the course of 18 weeks ?????

(this problem was not devised by Newton himself but is the product of folklore in mathematics)
i'll think about this one and come back later


Problem 10: (easy)

Express 1000 using the same digit exactly eight times... Basic arithmatic operations are permitted..... (1000= ....... + ,,,,,,,,, -''''''''''' + in this way)
division is considered a basic arithmetic operation
1000 = 1111-111 / 1
 
1:
Fill the 3 litre pot, then pour the three litres into the 5 litre pot. Refill the 3 litre pot and again pour the contents into the 5 litre pot, leaving 1 litre in the three litre pot. Empty the 5 litre pot, pour the 1 litre into the 5 litre pot, fill the 3 litre pot and then pour it into the 5 litre pot.


2:
Like Toopack said, I don't see how you can have three lots of 8 litres all at once.

3:
Number them 1-12

Weighing #1
Weigh 1, 2, 3 and 4 against 5, 6, 7 and 8
If they're balanced, then 9, 10, 11 or 12 is the deviant. See Weighing #2a
If the left side is heavier, then 1, 2, 3 or 4 is light OR 5, 6, 7 or 8 is heavy. See weighing #2b
If the right side is heavier, then 1, 2, 3 or 4 is heavy OR 5, 6, 7 or 8 is light. See weighing #2c

Weighing #2a (Possibilities: 9Light, 10Light, 11Light, 12Light, 9Heavy, 10Heavy, 11Heavy, 12Light)
Weigh 1, 2 and 3 against 9, 10 and 11
If they're balanced, goto Weighing #3a
If they're lighter, goto Weighing #3aa
If they're heavier, goto Weighing #3aaa)

Weighing #3a (Possibilities: 12Light, 12Heavy)
Weigh 1 against 12 to see whether 12 is heavier or lighter.

Weighing #3aa (Possibilities: 9Heavy, 10Heavy, 11Heavy)
Weigh 9 against 10. The heavier ball is the deviant. If they balance, 11 is the deviant.

Weighing #3aaa (Possibilities: 9Light, 10Light, 11Light)
Weigh 9 against 10. The lighter ball is the deviant. If they balance, 11 is the deviant.


Weighing #2b (Possibilities: 1Light, 2Light, 3Light, 4Light, 5Heavy, 6Heavy, 7Heavy, 8Heavy)
Weigh 1, 2 and 5 against 3, 4, and 6.
If they're balanced, goto Weighing #3b
If they're heavier, goto Weighing #3bb
If they're lighter, goto Weighing #3bbb

Weighing #3b (Possibilities: 7Heavy, 8Heavy)
Weigh 7 against 8. The heavier ball is the deviant.

Weighing #3bb (Possibilities: 3Light, 4Light, 5Heavy)
Weigh 3 against 4. The lighter ball is the deviant. If they're balanced, 5 is the deviant.

Weighing #3bbb (Possibilities: 1Light, 2Light, 6Heavy)
Weigh 1 against 2. The lighter ball is the deviant. If they're balanced, 6 is the deviant.

Weighing #2c (Possibilities: 5Light, 6Light, 7Light, 8Light, 1Heavy, 2Heavy, 3Heavy, 4Heavy)
Weigh 1, 2 and 5 against 3, 4, and 6.
If they're balanced, goto Weighing #3c
If they're heavier, goto Weighing #3cc
If they're lighter, goto Weighing #3ccc

Weighing #3c (Possibilities: 7Light, 8Light)
Weigh 7 against 8. The lighter ball is the deviant.

Weighing #3cc (Possibilities: 5Light, 3Heavy, 4Heavy)
Weigh 3 against 4. The heavier ball is the deviant. If they're balanced, 5 is the deviant.

Weighing #3ccc (Possibilities: 6Light, 1Heavy, 2Heavy)
Weigh 1 against 2. The heavier ball is the deviant. If they're balanced, 6 is the deviant.

Phew.

4:
Label the boxes 1 through to 11 and the balls based on the box they come from.

Take 1 ball from box 1, 2 from box 2 and so on, taking all 10 from box 10 and none from box 11.

Weigh these, and subtract the total weight from 550. This number is the number of the box. If the difference is 0, then box 11 contains the deviant balls.

5:
Arrange them in the shape of a pentagram.

6:
You're 49, you're dad's 99. Surprised he could even hear what you were saying, let alone respond.

7:
He was born on February 29th, giving him birthdays every four years from 1986 (excluding 1900, which isn't a leap year) to 1992.

8:
The 64 candles will burn for 64 hours.
The remainder of these 64 candles will give you another 8 full candles, burning for another 8 hours
The remainder of these 16 candles will give you another 1 full candle, burning for another hours
73 hours in total.

9 and 10 I'll get back to.
 
Illuminattile said:
1:
Fill the 3 litre pot, then pour the three litres into the 5 litre pot. Refill the 3 litre pot and again pour the contents into the 5 litre pot, leaving 1 litre in the three litre pot. Empty the 5 litre pot, pour the 1 litre into the 5 litre pot, fill the 3 litre pot and then pour it into the 5 litre pot.


2:
Like Toopack said, I don't see how you can have three lots of 8 litres all at once.

3:
Number them 1-12

Weighing #1
Weigh 1, 2, 3 and 4 against 5, 6, 7 and 8
If they're balanced, then 9, 10, 11 or 12 is the deviant. See Weighing #2a
If the left side is heavier, then 1, 2, 3 or 4 is light OR 5, 6, 7 or 8 is heavy. See weighing #2b
If the right side is heavier, then 1, 2, 3 or 4 is heavy OR 5, 6, 7 or 8 is light. See weighing #2c

Weighing #2a (Possibilities: 9Light, 10Light, 11Light, 12Light, 9Heavy, 10Heavy, 11Heavy, 12Light)
Weigh 1, 2 and 3 against 9, 10 and 11
If they're balanced, goto Weighing #3a
If they're lighter, goto Weighing #3aa
If they're heavier, goto Weighing #3aaa)

Weighing #3a (Possibilities: 12Light, 12Heavy)
Weigh 1 against 12 to see whether 12 is heavier or lighter.

Weighing #3aa (Possibilities: 9Heavy, 10Heavy, 11Heavy)
Weigh 9 against 10. The heavier ball is the deviant. If they balance, 11 is the deviant.

Weighing #3aaa (Possibilities: 9Light, 10Light, 11Light)
Weigh 9 against 10. The lighter ball is the deviant. If they balance, 11 is the deviant.


Weighing #2b (Possibilities: 1Light, 2Light, 3Light, 4Light, 5Heavy, 6Heavy, 7Heavy, 8Heavy)
Weigh 1, 2 and 5 against 3, 4, and 6.
If they're balanced, goto Weighing #3b
If they're heavier, goto Weighing #3bb
If they're lighter, goto Weighing #3bbb

Weighing #3b (Possibilities: 7Heavy, 8Heavy)
Weigh 7 against 8. The heavier ball is the deviant.

Weighing #3bb (Possibilities: 3Light, 4Light, 5Heavy)
Weigh 3 against 4. The lighter ball is the deviant. If they're balanced, 5 is the deviant.

Weighing #3bbb (Possibilities: 1Light, 2Light, 6Heavy)
Weigh 1 against 2. The lighter ball is the deviant. If they're balanced, 6 is the deviant.

Weighing #2c (Possibilities: 5Light, 6Light, 7Light, 8Light, 1Heavy, 2Heavy, 3Heavy, 4Heavy)
Weigh 1, 2 and 5 against 3, 4, and 6.
If they're balanced, goto Weighing #3c
If they're heavier, goto Weighing #3cc
If they're lighter, goto Weighing #3ccc

Weighing #3c (Possibilities: 7Light, 8Light)
Weigh 7 against 8. The lighter ball is the deviant.

Weighing #3cc (Possibilities: 5Light, 3Heavy, 4Heavy)
Weigh 3 against 4. The heavier ball is the deviant. If they're balanced, 5 is the deviant.

Weighing #3ccc (Possibilities: 6Light, 1Heavy, 2Heavy)
Weigh 1 against 2. The heavier ball is the deviant. If they're balanced, 6 is the deviant.

Phew.

4:
Label the boxes 1 through to 11 and the balls based on the box they come from.

Take 1 ball from box 1, 2 from box 2 and so on, taking all 10 from box 10 and none from box 11.

Weigh these, and subtract the total weight from 550. This number is the number of the box. If the difference is 0, then box 11 contains the deviant balls.

5:
Arrange them in the shape of a pentagram.

6:
You're 49, you're dad's 99. Surprised he could even hear what you were saying, let alone respond.

7:
He was born on February 29th, giving him birthdays every four years from 1986 (excluding 1900, which isn't a leap year) to 1992.

8:
The 64 candles will burn for 64 hours.
The remainder of these 64 candles will give you another 8 full candles, burning for another 8 hours
The remainder of these 8 candles will give you another 1 full candle, burning for another hours
73 hours in total.

9 and 10 I'll get back to.


what took you so long ... lol

anyways ill post some more just now , plus the answers
 

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