Interesting maths problem

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

Postby Rorschach » 06 Jan 2022, 12:49

Try not to give it away too easily if you get it. It had me confounded for a good few minutes!

230 - 220 x 0.5 = ?

You may not believe it, but the answer really is 5!
Bugger off.

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Re: Interesting maths problem

Postby Deebank » 06 Jan 2022, 13:27

Rorschach wrote:Try not to give it away too easily if you get it. It had me confounded for a good few minutes!

230 - 220 x 0.5 = ?

You may not believe it, but the answer really is 5!



Surely the most obvious answer? The one that immediately sprang to mind.
Why wouldn't I believe it? :?
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Re: Interesting maths problem

Postby OUTPLAY » 06 Jan 2022, 13:56

Yeah, it's obvious

230 minus 220 is 10

times that by 0.5 (i.e. half it), and you get 5
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Re: Interesting maths problem

Postby Positive Passion » 06 Jan 2022, 14:12

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.

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Re: Interesting maths problem

Postby souphound » 06 Jan 2022, 14:44

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.



That's the way I see it.
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Re: Interesting maths problem

Postby The Fish » 06 Jan 2022, 14:45

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.


That was my thought.
We're way past rhubarb

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Rorschach
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Re: Interesting maths problem

Postby Rorschach » 06 Jan 2022, 14:45

souphound wrote:
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.



That's the way I see it.


You're both correct in your logic.

There is some other trick. Look closely ...
Last edited by Rorschach on 06 Jan 2022, 14:49, edited 1 time in total.
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Rorschach
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Re: Interesting maths problem

Postby Rorschach » 06 Jan 2022, 14:47

double post
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Re: Interesting maths problem

Postby Positive Passion » 06 Jan 2022, 14:50

It is beyond a trick, really. If it were a footballer, it would be booked for diving.

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Re: Interesting maths problem

Postby Hightea » 06 Jan 2022, 15:14

souphound wrote:
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.



That's the way I see it.

yes unless someone is not using BIDMAS

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Rorschach
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Re: Interesting maths problem

Postby Rorschach » 06 Jan 2022, 15:14

Positive Passion wrote:It is beyond a trick, really. If it were a footballer, it would be booked for diving.


No it isn't!

Have you figured it out then? It's entirely correct mathematically.
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Re: Interesting maths problem

Postby Rorschach » 06 Jan 2022, 15:15

Hightea wrote:
souphound wrote:
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.



That's the way I see it.

yes unless someone is not using BIDMAS


They are using BIDMAS
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Re: Interesting maths problem

Postby Positive Passion » 06 Jan 2022, 15:35

Rorschach wrote:
Positive Passion wrote:It is beyond a trick, really. If it were a footballer, it would be booked for diving.


No it isn't!

Have you figured it out then? It's entirely correct mathematically.


Probably not. If you regard what looks like a decimal point as a full stop, then the operative phrase becomes 5 = 5, but I guess that is not the answer you are looking for.

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Re: Interesting maths problem

Postby souphound » 06 Jan 2022, 15:44

We are working with base-10 numbers, yes?
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Re: Interesting maths problem

Postby Positive Passion » 06 Jan 2022, 15:51

souphound wrote:We are working with base-10 numbers, yes?


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

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Re: Interesting maths problem

Postby The Prof » 06 Jan 2022, 16:23

It's to do with brackets, isn't it?

(230 - 220) x 0.5 = should be 5, no?

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Re: Interesting maths problem

Postby Positive Passion » 06 Jan 2022, 16:26

The Prof wrote:It's to do with brackets, isn't it?

(230 - 220) x 0.5 = should be 5, no?


Except that there aren't any brackets.

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Re: Interesting maths problem

Postby OUTPLAY » 06 Jan 2022, 17:14

If there aren't any brackets then the calculation is done in order, right?

Otherwise 230 - (220 x 0.5) which comes out as 120
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Re: Interesting maths problem

Postby Rorschach » 06 Jan 2022, 17:24

Positive Passion wrote:
Rorschach wrote:
Positive Passion wrote:It is beyond a trick, really. If it were a footballer, it would be booked for diving.


No it isn't!

Have you figured it out then? It's entirely correct mathematically.


Probably not. If you regard what looks like a decimal point as a full stop, then the operative phrase becomes 5 = 5, but I guess that is not the answer you are looking for.


No, it isn't.
Bugger off.

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Re: Interesting maths problem

Postby Rorschach » 06 Jan 2022, 17:27

OUTPLAY wrote:If there aren't any brackets then the calculation is done in order, right?

Otherwise 230 - (220 x 0.5) which comes out as 120


No. Calculations are done in the order BIDMAS/BODMAS: brackets, of (forget that one), division, multiplication, addition, and, finally, subtraction.

Which is: 230 - (220 x 0.5) which comes out as 120

Yet, amazingly, the correct answer is 5!

(Carlsson will get this in a heartbeat)
Bugger off.