Interesting maths problem

in reality, all of this has been a total load of old bollocks
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Hightea
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Re: Interesting maths problem

Postby Hightea » 06 Jan 2022, 19:24

oh brother 5! is 120
that's why I typically stay out of these silly things.

sorry it should have been: Yet, amazingly, the correct answer is 5!.
otherwise it just sounds that you are screaming the answer is 5.
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C
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Re: Interesting maths problem

Postby C » 06 Jan 2022, 19:54

Sorry, I am late to the party:

Positive Passion wrote:Surely one has to apply BIDMAS or whatever you call it, so you have
220 x .0.5 = 110.
Then
230 - 110 = 120.

If the answer really is 5 there's some other trick.


Correct and 120 = 5! = 5x4x3x2x1

There are no tricks in mathematics

When there are no brackets and with operations of different 'weight' multiplication/divison overrides addition/subtraction





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Last edited by C on 06 Jan 2022, 20:01, edited 2 times in total.
C wrote:Just blank the fucque-wit

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Re: Interesting maths problem

Postby C » 06 Jan 2022, 19:57

Positive Passion wrote:You to be working with at least base 6, because otherwise you couldn't have 0.5.


If we were working in base 6 - what would 0.5 represent in base 10...?

It obviously wouldn't be a half...




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C wrote:Just blank the fucque-wit

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Rorschach
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Re: Interesting maths problem

Postby Rorschach » 06 Jan 2022, 20:02

Hightea wrote:otherwise it just sounds that you are screaming the answer is 5.


That was kind of the point.
Bugger off.

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Re: Interesting maths problem

Postby Positive Passion » 06 Jan 2022, 20:13

C wrote:
Positive Passion wrote:You to be working with at least base 6, because otherwise you couldn't have 0.5.


If we were working in base 6 - what would 0.5 represent in base 10...?

It obviously wouldn't be a half...




.


5/6, which is about 83%, or 0.83 and change

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Re: Interesting maths problem

Postby souphound » 06 Jan 2022, 20:14

C wrote:
Positive Passion wrote:You to be working with at least base 6, because otherwise you couldn't have 0.5.


If we were working in base 6 - what would 0.5 represent in base 10...?

It obviously wouldn't be a half...




.


0.83333333333333333333333333333333333333333333333333333333333333..........?
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Re: Interesting maths problem

Postby souphound » 06 Jan 2022, 20:16

And you may note that a "3" is really only the right half of an "8".
Footy wrote:Last week, I discovered that the cordless drill I bought about 5 years ago is, in fact, a cordless screwdiver.

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Re: Interesting maths problem

Postby Rorschach » 06 Jan 2022, 20:30

souphound wrote:And you may note that a "3" is really only the right half of an "8".



:o
Bugger off.

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Re: Interesting maths problem

Postby souphound » 06 Jan 2022, 20:33

Rorschach wrote:
souphound wrote:And you may note that a "3" is really only the right half of an "8".



:o


You can use the "!" to chop down the "8" if you want.



:D
Footy wrote:Last week, I discovered that the cordless drill I bought about 5 years ago is, in fact, a cordless screwdiver.

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Re: Interesting maths problem

Postby Positive Passion » 06 Jan 2022, 20:47

Rorschach wrote:
souphound wrote:And you may note that a "3" is really only the right half of an "8".



:o


:o

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Re: Interesting maths problem

Postby C » 06 Jan 2022, 22:34

Positive Passion wrote:
C wrote:
Positive Passion wrote:You to be working with at least base 6, because otherwise you couldn't have 0.5.


If we were working in base 6 - what would 0.5 represent in base 10...?

It obviously wouldn't be a half...




.


5/6, which is about 83%, or 0.83 and change


Correct - but how would you explain that....?



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C wrote:Just blank the fucque-wit

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Re: Interesting maths problem

Postby Deebank » 07 Jan 2022, 09:14

Sometimes it pays to be ignorant.
I've been talking about writing a book - 25 years of TEFL - for a few years now. I've got it in me.

Paid anghofio fod dy galon yn y chwyldro

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Re: Interesting maths problem

Postby C » 07 Jan 2022, 09:55

Positive Passion wrote:
C wrote:
Positive Passion wrote:You to be working with at least base 6, because otherwise you couldn't have 0.5.


If we were working in base 6 - what would 0.5 represent in base 10...?

It obviously wouldn't be a half...




.


5/6, which is about 83%, or 0.83 and change


The 5/6 is correct but in base 6 does that equate to 0.83...?

Are you not applying base 10 mathematics to a base 6 problem when carrying out the division to change the fraction to a decimal...?

For others:

In base 6 for example 35 can't be read as 'thirty-five', [we read it as 'three-five'], because in this example 35 is 3 sixes and 5 units which equals 23 (base 10).

Questions for those interested

23 (base 4) + 33 (base 4)

621 (base 7) - 155 (base 7)

Incidentally, when I was at school questions like the above we were doing when I was 9 years old. All kids did it because, in the UK, we had systems that did not use the denary/decimal system

Different number bases were part of the primary curriculum

12 pence = 1 shilling
20 shillings = £1
12 inches = 1 foot
3 feet = I yard
16 ounces = 1 pound
112 pounds = 1 hundredweight
8 furlongs = 1 mile



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C wrote:Just blank the fucque-wit

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Re: Interesting maths problem

Postby Positive Passion » 07 Jan 2022, 11:36

C wrote:
Positive Passion wrote:
C wrote:
If we were working in base 6 - what would 0.5 represent in base 10...?

It obviously wouldn't be a half...




.


5/6, which is about 83%, or 0.83 and change


The 5/6 is correct but in base 6 does that equate to 0.83...?

Are you not applying base 10 mathematics to a base 6 problem when carrying out the division to change the fraction to a decimal...?




You asked what the base 10 equivalent of 0.5 in base 6 was.
In base 6, 5/6 would be 0.5.
It is about recognising place value.
Last edited by Positive Passion on 07 Jan 2022, 13:58, edited 1 time in total.

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Re: Interesting maths problem

Postby souphound » 07 Jan 2022, 13:49

C wrote:
Positive Passion wrote:
C wrote:
Incidentally, when I was at school questions like the above we were doing when I was 9 years old. All kids did it because, in the UK, we had systems that did not use the denary/decimal system


.


Reading this, I infer that when you turned 10, everything went to decimal?

:)

Sorry. Carry on.
Footy wrote:Last week, I discovered that the cordless drill I bought about 5 years ago is, in fact, a cordless screwdiver.

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Re: Interesting maths problem

Postby C » 07 Jan 2022, 18:13

Positive Passion wrote:
C wrote:
Positive Passion wrote:
5/6, which is about 83%, or 0.83 and change


The 5/6 is correct but in base 6 does that equate to 0.83...?

Are you not applying base 10 mathematics to a base 6 problem when carrying out the division to change the fraction to a decimal...?




You asked what the base 10 equivalent of 0.5 in base 6 was.
In base 6, 5/6 would be 0.5.
It is about recognising place value.


Absolutely correct. It was the 0.8333... bit I was highlighting



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C wrote:Just blank the fucque-wit

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Re: Interesting maths problem

Postby C » 07 Jan 2022, 18:13

souphound wrote:
C wrote:
Positive Passion wrote:


Reading this, I infer that when you turned 10, everything went to decimal?

:)

Sorry. Carry on.


:lol:



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C wrote:Just blank the fucque-wit

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Re: Interesting maths problem

Postby Darkness_Fish » 07 Jan 2022, 19:31

There are 10 kinds of people.
Those who understand hexadecimal and those who don't understand hexadecimal. The friends of people who understand hexadecimal, but don't themselves understand hexadecimal. The friends of people who do understand hexadecimal, and also understand hexadecimal. Then there are those who wish they'd chosen a smaller base before starting a joke. Then the friends of those who wish...
Like fast-moving clouds casting shadows against a hillside, the melody-loop shuddered with a sense of the sublime, the awful unknowable majesty of the world.

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Re: Interesting maths problem

Postby Rorschach » 07 Jan 2022, 21:29

Darkness_Fish wrote:...Then there are those who wish they'd chosen a smaller base before starting a joke ...


:)

Maybe try base 3 next time. (Binary's been done to death.)
Bugger off.

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Re: Interesting maths problem

Postby Charlie O. » 08 Jan 2022, 04:33




(Lehrer's "day job" at the time [1965]. and for many years before and after, was lecturing on mathematics at MIT, Harvard, and others of that ilk.)
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