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#1 2010-06-19 21:16:18
- atut
- Member
- Registered: 2008-04-23
- Posts: 30
Maths Problem
You have four different numbers:
21
20
22
6
You have to find out how to get the number 24
You can only use addition, subtraction multiplication and division, anything beyond that is not allowed.
Please can you work it out 
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#2 2010-06-19 21:20:23
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Maths Problem
Hi atut;
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 2010-06-19 21:27:44
- atut
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- Registered: 2008-04-23
- Posts: 30
Re: Maths Problem
you cannot do that because:
22-20 = 2 but the next sum has to have the 2 at the beginning of the sum:
22-20 then you have to do 2/6 which equals 0.33 recuring.
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#4 2010-06-19 21:35:37
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Maths Problem
Hi atut;
6 / 2 = 3 and 3 + 21 = 24
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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#5 2010-06-19 21:40:11
- atut
- Member
- Registered: 2008-04-23
- Posts: 30
Re: Maths Problem
you have to use 2 as the first number in the next sum
all numbers should be used as well
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#6 2010-06-19 21:42:55
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Maths Problem
Hi atut;
You want to break the numbers apart? I am not following you? Can you show an example one?
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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#7 2010-06-19 21:47:49
- atut
- Member
- Registered: 2008-04-23
- Posts: 30
Re: Maths Problem
This is an example
four numbers:
11
8
10
6
the answer = 11-8=3 3x10 = 30 30-6=24
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#8 2010-06-19 21:59:27
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Maths Problem
Must they be in that order or can you use a different order?
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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#9 2010-06-19 22:00:19
- atut
- Member
- Registered: 2008-04-23
- Posts: 30
Re: Maths Problem
whcih numbers?
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#10 2010-06-19 22:09:44
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Maths Problem
21 20 22 6
Do I have to use them in that order or can I use them in some other order like 6 20 22 21 ?
Cause I have
22 - 20 =2
6 / 2 = 3
3 + 21 = 24
How many rules did I violate?
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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#11 2010-06-19 22:18:23
- atut
- Member
- Registered: 2008-04-23
- Posts: 30
Re: Maths Problem
you have to use all the numbers in any order but if u get a number like :
22-20 = 2
then u have to use 2 in the next sum first:
2/6 = 0.3 recuring
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#12 2010-06-19 22:19:55
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Maths Problem
Hi;
How's this?
22 - 20 =2
6 / 2 = 3
3 + 21 = 24
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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#13 2010-06-19 23:00:29
- atut
- Member
- Registered: 2008-04-23
- Posts: 30
Re: Maths Problem
2 has to be the subject of the new sum:
like this
2/6
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#14 2010-06-20 16:06:38
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Maths Problem
Hi atut;
I think I have the rules finally! That was a big step for me. So far I don't have a solution though.
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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#15 2010-06-20 19:00:30
- phrontister
- Real Member
- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 4,861
Re: Maths Problem
...the rules...
But wait! Maybe there are more!!
Thinking in calculator mode:
1. Is the use of the equals sign other than as the usual sum termination allowed?
2. Can equals signs be mixed in with operators?
3. Are adjacent operators allowed?
4. What about adjacent equals signs?
In my common-garden-variety scientific calculator the equals sign acts as a constant that repeats the previous combined operator and number input. For this problem it repeats the previous addition, subtraction, multiplication or division action.
Here are some examples:
All four examples can be expanded into separate steps that obey the rule that a step's result must be the subject of the next step.
May the four numbers (6, 20, 21 & 22) be used more than once? If so, then the above answers can be expressed differently to allow for that. There are other solutions too.
And if the rules won't allow any of those options, I'm taking my bat & ball and I'm going home! 
>humph<
Last edited by phrontister (2010-06-21 12:20:10)
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