Maths Problem  - 10 May

A worker is to perform work for you for seven straight days. In return for his
work, you will pay him 1/7th of a bar of gold per day. The worker requires a
daily payment of 1/7th of the bar of gold. What and where are the fewest number
of cuts to the bar of gold that will allow you to pay him 1/7th each day ?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day

[Non-text portions of this message have been removed]

Mismatch Sum Puzzle  - 14 May

A bank customer had £100 in his account. He then made 6 withdrawals, totaling
£100. He kept a record of these withdrawals, and the balance remaining in the
account, as follows: 


Withdrawals
Balance left
£50 £50
£25 £25
£10 £15
£8 £7
£5 £2
£2 £0

________________________________

________________________________

£100 £99

Why are the Totals not exactly right ?

Update Your Answers at : Click Here

Solution
WILL BE UPDATED IN 1 DAY



-- 
 
                    "Never explain yourself. Your friends don’t need
it and your enemies won’t believe it" .


[Non-text portions of this message have been removed]

What if there was just one transaction:

Withdrawal    Balance left
----------    ------------
£100          £0
----------    ------------
Totals:
£100          £0


Why are those numbers not equal?   For the same reason as the original problem. 
One is the total withdrawals, and the other is the sum of a series of balances -
two totally different concepts.


--- In mathforfun@yahoogroups.com, lavesh rawat <love19_foryou@...> wrote:
>
> Mismatch Sum Puzzle  - 14 May
>
> A bank customer had £100 in his account. He then made 6 withdrawals, totaling
£100. He kept a record of these withdrawals, and the balance remaining in the
account, as follows: 
>
>
> Withdrawals
> Balance left
> £50 £50
> £25 £25
> £10 £15
> £8 £7
> £5 £2
> £2 £0
>
> ________________________________
>
> ________________________________
>
> £100 £99
>
> Why are the Totals not exactly right ?
>
> Update Your Answers at : Click Here
>
> Solution
> WILL BE UPDATED IN 1 DAY
>
>
>
> -- 
>  
>                     "Never explain yourself. Your friends don’t
need it and your enemies won’t believe it" .
>
>
> [Non-text portions of this message have been removed]
>

There are an infinite number of pairs a_i > b_i. Moreover the number with a_i <
b_i, is finite.

Proof: The number of natural numbers k or fewer digits in length that can be
constructed with only 9 symbols (including 0) is the same as the number of base
9 numbers with k or fewer digits which is just 9^k.

If 0 is the excluded digit, it's more complicated: (9^(k+1)-9)/8 instead of 9^k,
but I'll assume it's 9^k for clarity.

Let a_i be k digits long. Then i can't be more than the number of a's with k or
fewer digits: i <= 9^k. Combining that with the fact that a_i >= 10^(k-1) gives:

a_i/i >= (1/10)*(10/9)^k

The ratio increases exponentially with k. Let's require k >= 29 making it at
least 2:

a_i/i > 2

Let b_j be the highest b below a_i. a_i is equal to the sum of the totals of a's
and b's below or equal to a_i:

i + j = a_i > 2*i
==> j > i

So b_i < b_j < a_i, that is, a_i > b_i for every a_i >= 10^28.

Mark


--- In mathforfun@yahoogroups.com, "iptoc" <iptoc@...> wrote:
>
> There are two sequences of natural numbers. The first sequence
> consists of all natural numbers that do not contain a particular
> digit, in ascending order. The second sequence consists of all
> the remaining natural numbers in ascending order. Every natural
> number occurs exactly once in exactly one of the sequences.
>
> How many terms are there in the first sequence such that each of
> those terms is greater than the corresponding term at the same
> position in the second sequence?
>
> In other words, if (a_1, a_2, ...) is the first sequence and
> (b_1, b_2, ...) is the second sequence how many elements a_i are
> there in the first sequence such that a_i > b_i?
>
> --
> Originally posted at: http://cotpi.com/p/50/
> Correct solutions will be archived at the URL mentioned above.
> Solutions to 'Powers of ten': http://cotpi.com/p/49/#responses
>
> Google+: http://plus.google.com/108698297184243273330
>

Place the metal together so that the end of one bar touches the middle of the
other bar.

Repeat but reverse the process.  (i.e. end of the second bar touching the middle
of the first bar.)

The ends of the magnetic bar will grab firmly to the middle of the other bar,
but the the middle of it will not grab firmly to the end of of the nonmagnetic
one.

--- In mathforfun@yahoogroups.com, lavesh rawat <love19_foryou@...> wrote:
>
> Famous Science Problem  - 7 May 
>
> You are in a room with no metal objects except for two iron  bars . Only one
of them is a magnet.
> How can you identify which one is a magnet?.

Two Door Riddle  - 23 May

You find yourself in a strange place guarded by two guards.One of the guard
always say truth while other always lies.You dont know the identity of the
two.You can ask only one question to go out from there. What should you ask?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day




-- 
 
                    "Never explain yourself. Your friends don’t need
it and your enemies won’t believe it" .


[Non-text portions of this message have been removed]

What is the problem asking?  How to get out of the place?  Why not just walk
out?  What good would question asking do?

--- In mathforfun@yahoogroups.com, lavesh rawat <love19_foryou@...> wrote:
>
> Two Door Riddle  - 23 May
>
> You find yourself in a strange place guarded by two guards.One of the guard
always say truth while other always lies.You dont know the identity of the
two.You can ask only one question to go out from there. What should you ask?

Easy math puzzle  - 24 May

I am the owner of a birds store. If I put in one bird per cage, I have one bird
too many. If I put in two bird per cage, I have one cage too many. How many
cages and birds do I have?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day



-- 
 
                    "Never explain yourself. Your friends don’t need
it and your enemies won’t believe it" .


[Non-text portions of this message have been removed]

4 birds3 cage.
To:
From: love19_foryou@...
Date: Thu, 24 May 2012 16:00:08 +0800
Subject: [MATH for FUN] [Daily Brain Teaser] Easy math puzzle


























       Easy math puzzle  - 24 May



I am the owner of a birds store. If I put in one bird per cage, I have one bird
too many. If I put in two bird per cage, I have one cage too many. How many
cages and birds do I have?



Update Your Answers at : Click Here



Solution

Will be updated after 1 day



--



                     "Never explain yourself. Your friends don’t need it and your
enemies won’t believe it" .



[Non-text portions of this message have been removed]


















[Non-text portions of this message have been removed]

Logic Puzzle  - 28 May

A cat, a dog and a monkey were stolen. 3 suspects got caught: Harish,
Manoj and Tarun. All we know that each person stole one animal, but we
do not know who stole which. Here are the investigation statements.
Harish said: Tarun stole the cat. Manoj said: Tarun stole the dog. Tarun said:
They both were lying. I did not steal the cat or the dog. Later
on, the police found out the man who stole the monkey told a lie. The
man who stole the cat told the truth. Can you find out who stole which?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day

[Non-text portions of this message have been removed]

A cat, a dog and a monkey were stolen. 3 suspects got caught: Harish, Manoj and
Tarun. All we know that each person stole one animal, but we do not know who
stole which. Here are the investigation statements.


Harish said: Tarun stole the cat. Manoj said: Tarun stole the dog. Tarun said:
They both were lying. I did not steal the cat or the dog.

Later on, the police found out the man who stole the monkey told a lie.

The man who stole the cat told the truth. Can you find out who stole which?

Case 1: If Tarun stole the cat.
This means that Tarun told the truth, so Harish and Manoj were lying and Tarun
did not steal the cat or the dog. Contradiction with our assumption.

SO, case 2 it's true: Tarun did not stole the cat.

So T stole the monkey or the dog.
So H lied, and T lied. We have somebody that told the truth, so M told the true,
so M stole the cat.
M told the true, so T stole the dog, and H stole the monkey.

i verified again the problem and this solution verify all the conditions. (T
lies.)

[Non-text portions of this message have been removed]

Solve The Riddle  - 29 May

A car meter reading shows 72927 miles a palindromic number.
what is the minimum number of miles you would need to travel to see another
palindromic number on the car meter reading?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day

[Non-text portions of this message have been removed]

10100 miles.
 
Tofique Fatehi
Mumbai, INDIA


________________________________
From: lavesh rawat <love19_foryou@...>
To:
Sent: Tuesday, May 29, 2012 12:45 PM
Subject: [MATH for FUN] [Daily Brain Teaser] Solve The Riddle - 29 May


 
Solve The Riddle  - 29 May

A car meter reading shows 72927 miles a palindromic number.
what is the minimum number of miles you would need to travel to see another
palindromic number on the car meter reading?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day

[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]

110 miles, making 73037 miles.

stevo

On Tue, May 29, 2012 at 10:36 AM, Tofique Fatehi <tofiquef@...> wrote:

> **
>
>
> 10100 miles.
>
> Tofique Fatehi
> Mumbai, INDIA
>
> ________________________________
> From: lavesh rawat <love19_foryou@...>
> To:
> Sent: Tuesday, May 29, 2012 12:45 PM
> Subject: [MATH for FUN] [Daily Brain Teaser] Solve The Riddle - 29 May
>
>
>
> Solve The Riddle  - 29 May
>
> A car meter reading shows 72927 miles a palindromic number.
> what is the minimum number of miles you would need to travel to see
> another palindromic number on the car meter reading?
>
> Update Your Answers at : Click Here
>
> Solution
> Will be updated after 1 day
>
> [Non-text portions of this message have been removed]
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]

1010 miles, making 73937 on the meter.

stevo

On Tue, May 29, 2012 at 3:15 AM, lavesh rawat <love19_foryou@...>wrote:

> **
>
>
> Solve The Riddle  - 29 May
>
> A car meter reading shows 72927 miles a palindromic number.
> what is the minimum number of miles you would need to travel to see
> another palindromic number on the car meter reading?
>
> Update Your Answers at : Click Here
>
> Solution
> Will be updated after 1 day
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]

Logic Riddle  - 1 June

An infinite number of mathematicians are standing behind a bar. The first asks
the barman for half a pint of beer, the second for a quarter pint, the third an
eighth, and so on. How many pints of beer will the barman need to fulfill all
mathematicians' wishes?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day

[Non-text portions of this message have been removed]

Just one.

stevo

On Fri, Jun 1, 2012 at 3:05 AM, lavesh rawat <love19_foryou@...>wrote:

> **
>
>
> Logic Riddle  - 1 June
>
> An infinite number of mathematicians are standing behind a bar. The first
> asks the barman for half a pint of beer, the second for a quarter pint, the
> third an eighth, and so on. How many pints of beer will the barman need to
> fulfill all mathematicians' wishes?
>
> Update Your Answers at : Click Here
>
> Solution
> Will be updated after 1 day
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]

Math Puzzle Kids  - 4 June

Anmol had a bag containing colorful marbles. The colors are red, green and blue.
The total number of marbles he had in his bag is 60. There are 4 times as many
red marbles as green marbles. 6 more blue marbles than green marbles. How many
marbles of each color did Anmol have?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day


-- 
 
                    "Never explain yourself. Your friends don’t need
it and your enemies won’t believe it" .


[Non-text portions of this message have been removed]

Green=9, Red=36, Blue=15



________________________________
From: lavesh rawat <love19_foryou@...>
To:
Sent: Monday, 4 June 2012 6:23 PM
Subject: [MATH for FUN] [Daily Brain Teaser] Math Puzzle Kids


 
Math Puzzle Kids  - 4 June

Anmol had a bag containing colorful marbles. The colors are red, green and blue.
The total number of marbles he had in his bag is 60. There are 4 times as many
red marbles as green marbles. 6 more blue marbles than green marbles. How many
marbles of each color did Anmol have?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day

-- 
 
                    "Never explain yourself. Your friends don’t need
it and your enemies won’t believe it" .

[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]

Suppose there are n points and each pair is connected by a 1 ohm resistor
(n(n-1)/2 resistors in all). What's the resistance between any two points?

R = 2/n

--- In mathforfun@yahoogroups.com, "video_ranger" <markjones76@...> wrote:
>
> Suppose there are n points and each pair is connected by a 1 ohm resistor
(n(n-1)/2 resistors in all). What's the resistance between any two points?
>

Imagine a checkerboard in which all (144) line segments are 1-ohm resistors
connected at the intersections (vertices). So each of the 64 vertices is
connected to 4,3, or 2 resistors depending on whether it's interior, on a side,
or a corner.

Suppose one of the resistors is selected at random and the resistance across its
terminals (while connected in the network) measured. What's the expectation
value?

Mark


--- In mathforfun@yahoogroups.com, "JonDihon" <cooperpuzzles@...> wrote:
>
> R = 2/n
>
> --- In mathforfun@yahoogroups.com, "video_ranger" <markjones76@> wrote:
> >
> > Suppose there are n points and each pair is connected by a 1 ohm resistor
(n(n-1)/2 resistors in all). What's the resistance between any two points?
> >
>

Correction: there are 81 vertices on a chessboard (not 64).

--- In mathforfun@yahoogroups.com, "video_ranger" <markjones76@...> wrote:
>
> Imagine a checkerboard in which all (144) line segments are 1-ohm resistors
connected at the intersections (vertices). So each of the 64 vertices is
connected to 4,3, or 2 resistors depending on whether it's interior, on a side,
or a corner.
>
> Suppose one of the resistors is selected at random and the resistance across
its terminals (while connected in the network) measured. What's the expectation
value?
>
> Mark
>
>
> --- In mathforfun@yahoogroups.com, "JonDihon" <cooperpuzzles@> wrote:
> >
> > R = 2/n
> >
> > --- In mathforfun@yahoogroups.com, "video_ranger" <markjones76@> wrote:
> > >
> > > Suppose there are n points and each pair is connected by a 1 ohm resistor
(n(n-1)/2 resistors in all). What's the resistance between any two points?
> > >
> >
>

Coin Riddle  - 13 June

If you were to put a coin into an empty bottle and then insert a cork into the
neck, how could you remove the coin without taking out the cork or breaking the
bottle?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day



-- 
 
                    "Never explain yourself. Your friends don’t need
it and your enemies won’t believe it" .


[Non-text portions of this message have been removed]

Push the cork into the bottle & remove the coin...


________________________________
  From: lavesh rawat <love19_foryou@...>
To:
Sent: Wednesday, 13 June 2012 1:24 PM
Subject: [MATH for FUN] [Daily Brain Teaser] Coin Riddle


 
Coin Riddle  - 13 June

If you were to put a coin into an empty bottle and then insert a cork into the
neck, how could you remove the coin without taking out the cork or breaking the
bottle?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day

-- 
 
                    "Never explain yourself. Your friends don’t need
it and your enemies won’t believe it" .

[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]

Push (or suck) the cork all the way into the bottle, freeing the opening?

stevo

On Wed, Jun 13, 2012 at 3:54 AM, lavesh rawat <love19_foryou@...>wrote:

> **
>
>
> Coin Riddle  - 13 June
>
> If you were to put a coin into an empty bottle and then insert a cork into
> the neck, how could you remove the coin without taking out the cork or
> breaking the bottle?
>
> Update Your Answers at : Click Here
>
> Solution
> Will be updated after 1 day
>
> --
>
>                     "Never explain yourself. Your friends don’t need it
> and your enemies won’t believe it" .
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]

Number Series  - 15 June

What is the next number in this series, 1, 11, 21, 1211, 111221 , 312211 ?

Update Your Answers at : Click Here

Solution
Will be updated after 1 day

-- 
 
                    "Never explain yourself. Your friends don’t need
it and your enemies won’t believe it" .

[Non-text portions of this message have been removed]

13112221

A pretty old and well known problem.

--- In mathforfun@yahoogroups.com, lavesh rawat <love19_foryou@...> wrote:
>
> Number Series  - 15 June
>
> What is the next number in this series, 1, 11, 21, 1211, 111221 , 312211 ?
>
> Update Your Answers at : Click Here
>
> Solution
> Will be updated after 1 day

Lavesh Rawat, from India, is copying puzzles from everywhere on the Internet and
posting them to his blog: http:// dailybrainteaser. blogspot. com/ without
giving any credit to the source of the actual puzzles.

There are multiple copies of each puzzle on the internet that are available on
his website. Shouldn't we discourage this act of plagiarism?

Lavesh Rawat, from India, is copying puzzles from everywhere on the Internet and
posting them to his blog: http:// dailybrainteaser. blogspot. com/ without
giving any credit to the source of the actual puzzles.

There are multiple copies of each puzzle on the internet that are available on
his website. Shouldn't we discourage this act of plagiarism?