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#1 2015-05-12 16:40:39

prudhvi123
Guest

Try to Answer this hard question.

Hello, I have puzzle to solve can you please help me out?
Make 5 rupees using 5 paisa , 20 paisa and 50 paisa, there should be only 20 coins.

#2 2015-05-12 19:07:54

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Try to Answer this hard question.

As I understand the question a rupee equals 100 paisa. If you have 5 paise coins, 20 paise coins and 50 paise coins then there are no solutions to the problem.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#3 2015-05-12 19:26:58

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,810

Re: Try to Answer this hard question.

Ditto.


"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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#4 2015-05-15 11:31:27

math9maniac
Member
From: Tema
Registered: 2015-03-30
Posts: 443

Re: Try to Answer this hard question.

Let p = paisa and r = rupee
If 1r = 100p, it follows that 5r = 500p.
Now, using 20 coins, the closest I get to 500p is 490p, where there  are seven 50p coins, five 20p coins and eight 5p coins.
However, to obtain exactly 5r or 500p requires 22 coins where you add 2 more 5p coins to make 10 of 5p coins.


Only a friend tells you your face is dirty.

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#5 2015-05-15 12:28:59

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Try to Answer this hard question.

You can make 505, in exactly 6 ways.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#6 2015-05-15 13:33:30

math9maniac
Member
From: Tema
Registered: 2015-03-30
Posts: 443

Re: Try to Answer this hard question.

How bobbym? Pls share.


Only a friend tells you your face is dirty.

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#7 2015-05-15 13:36:51

math9maniac
Member
From: Tema
Registered: 2015-03-30
Posts: 443

Re: Try to Answer this hard question.

Or better still let's see if I can figure that out.  It's way past midnight here (01:33am). My eyes heavy. Hear from me tomorrow, no, in fact I mean later today when I wake up to some good sunshine.


Only a friend tells you your face is dirty.

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#8 2015-05-15 23:43:47

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,810

Re: Try to Answer this hard question.

Hi;

bobbym wrote:

You can make 505, in exactly 6 ways.

Yes, that's what I got too.

math9maniac wrote:

However, to obtain exactly 5r or 500p requires 22 coins where you add 2 more 5p coins to make 10 of 5p coins.

22 coins can make 500 in 7 ways.

Including the 22-coin option, there are 31 different quantity options that can make 500, in a total of 146 different ways:

eg,
16 coins can make 500 in 4 ways;
28 coins can make 500 in 9 ways;
37 coins can make 500 in 8 ways;
58 coins can make 500 in 5 ways;
76 coins can make 500 in 3 ways.

Last edited by phrontister (2015-05-18 15:44:58)


"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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#9 2015-05-16 10:24:33

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Try to Answer this hard question.

How bobbym? Pls share.

It is done with diophantine equations and or by computer.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#10 2015-05-17 02:06:13

phrontister
Real Member
From: The Land of Tomorrow
Registered: 2009-07-12
Posts: 4,810

Re: Try to Answer this hard question.

Hi;

bobbym wrote:

......there are no solutions to the problem.

I reasoned it this way:

Last edited by phrontister (2015-05-17 11:21:13)


"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

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#11 2015-05-17 08:35:51

math9maniac
Member
From: Tema
Registered: 2015-03-30
Posts: 443

Re: Try to Answer this hard question.

Pls forgive if I don't know but what is diophantine?


Only a friend tells you your face is dirty.

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#12 2015-05-17 09:27:41

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: Try to Answer this hard question.

It has come to mean equations that only have integer solutions.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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