"Viral" maths problem

Cerebral distractions of every kind, mostly but not exclusively Countdown-related.

Moderator: Michael Wallace

Post Reply
Gavin Chipper
Post-apocalypse
Posts: 13194
Joined: Mon Jan 21, 2008 10:37 pm

"Viral" maths problem

Post by Gavin Chipper »

I saw this come up on Facebook a day or so ago from The Mirror, so I thought I'd post it here. It's nothing original - I've seen similar before. It's also here.

What is 6 ÷ 2(1+2) ?

I'll be back to discuss.
User avatar
Johnny Canuck
Kiloposter
Posts: 1647
Joined: Sun Oct 03, 2010 10:44 pm
Location: Montréal 😃, Québec 😕, Canada 😃

Re: "Viral" maths problem

Post by Johnny Canuck »

Nine. Simple BEDMAS: do the bracket to get 6/2*3, then multiplication and division left to right. This is objectively the only answer.
I'm not dead yet. In a rut right now because of stress from work. I'll be back later in S89. I also plan to bring back the Mastergram - if I can find a way to run a timer or clock through pure MediaWiki without having to upload to Vimeo every time.
User avatar
Matt Morrison
Post-apocalypse
Posts: 7822
Joined: Wed Oct 22, 2008 2:27 pm
Location: London
Contact:

Re: "Viral" maths problem

Post by Matt Morrison »

If a(b+c) == ab + ac isn't it 1?

Not done maths in many years so don't remember the rules as to when you would expand the brackets.
Gavin Chipper
Post-apocalypse
Posts: 13194
Joined: Mon Jan 21, 2008 10:37 pm

Re: "Viral" maths problem

Post by Gavin Chipper »

If you read the explanation in the second link I gave or watch this video, they're quite clear that the answer is 9.

However, I think to talk about it simply in terms of BEDMAS/BODMAS/BIDMAS/TISWAS is to miss the point about where the confusion or potential ambiguity lies. And the website and video do not address this.

We have 6 ÷ 2(1+2). If it was written as 6 ÷ 2 x (1+2) then pretty much everyone would agree that it is 9 and there would be no problem. The confusion comes from not putting the multiplication sign in leaving just 2(1+2) all stuck together because it looks like it is a term in the equation itself. Another example in the video is 1 ÷ 2y (even though as mentioned the video doesn't address the underlying source of confusion). Should that be taken as 1 / 2 * y, or 1 / (2y)?

The "correct" answer I suppose would just be whatever some committee of mathematical notation decides. It's not really a mathematical problem and talking of BEDMAS/BODMAS/BIDMAS/TISWAS does not resolve the problem either. But it is a poorly worded question and you'd never get anything written like that in "real life" outside a problem designed to deliberately confuse.

But aside fron the "correct" answer, we can still discuss what we think the aforementioned committee should reasonably decide. And I think if a number is put adjcent to the brackets like that with no multiplication sign then it's more reasonable to conclude that it goes with what's in the brackets so that they're treated as a single term. And that would make the answer 1. But because it's debatable and not everyone would agree, no-one should ever write a formula like that.
Sam Cappleman-Lynes
Enthusiast
Posts: 266
Joined: Sun Apr 07, 2013 11:30 pm

Re: "Viral" maths problem

Post by Sam Cappleman-Lynes »

Gavin Chipper wrote: Mon Nov 16, 2020 12:45 pm But because it's debatable and not everyone would agree, no-one should ever write a formula like that.
This is the only correct answer.
User avatar
Ian Fitzpatrick
Devotee
Posts: 614
Joined: Sat Jan 31, 2009 12:23 pm
Location: Wimborne, Dorset

Re: "Viral" maths problem

Post by Ian Fitzpatrick »

Sam Cappleman-Lynes wrote: Mon Nov 16, 2020 2:50 pm
Gavin Chipper wrote: Mon Nov 16, 2020 12:45 pm But because it's debatable and not everyone would agree, no-one should ever write a formula like that.
This is the only correct answer.
Totally agree
I thought I was good at Countdown until I joined this forum
Tom S
Kiloposter
Posts: 1271
Joined: Wed Oct 11, 2017 1:38 pm

Re: "Viral" maths problem

Post by Tom S »

1
User avatar
Johnny Canuck
Kiloposter
Posts: 1647
Joined: Sun Oct 03, 2010 10:44 pm
Location: Montréal 😃, Québec 😕, Canada 😃

Re: "Viral" maths problem

Post by Johnny Canuck »

Matt Morrison wrote: Mon Nov 16, 2020 9:52 am ==
Found a fellow programmer. Hello world.
I'm not dead yet. In a rut right now because of stress from work. I'll be back later in S89. I also plan to bring back the Mastergram - if I can find a way to run a timer or clock through pure MediaWiki without having to upload to Vimeo every time.
User avatar
Matt Morrison
Post-apocalypse
Posts: 7822
Joined: Wed Oct 22, 2008 2:27 pm
Location: London
Contact:

Re: "Viral" maths problem

Post by Matt Morrison »

Code: Select all

const printThisShitOut = `Gevin is in love with ${c4c.filter(c => !!c.cool).join(" and ")} and he is a prick.`;
Fiona T
Kiloposter
Posts: 1441
Joined: Mon Mar 18, 2019 12:54 pm

Re: "Viral" maths problem

Post by Fiona T »

Matt Morrison wrote: Fri Nov 20, 2020 11:45 pm

Code: Select all

const printThisShitOut = `Gevin is in love with ${c4c.filter(c => !!c.cool).join(" and ")} and he is a prick.`;
Gevin's in love with himself ;)
Gavin Chipper
Post-apocalypse
Posts: 13194
Joined: Mon Jan 21, 2008 10:37 pm

Re: "Viral" maths problem

Post by Gavin Chipper »

Someone has to be.
User avatar
Matt Morrison
Post-apocalypse
Posts: 7822
Joined: Wed Oct 22, 2008 2:27 pm
Location: London
Contact:

Re: "Viral" maths problem

Post by Matt Morrison »

Damn I must've been drunk. Saw you quoting that and I thought I must've made that post years ago, not last night.
Fiona T
Kiloposter
Posts: 1441
Joined: Mon Mar 18, 2019 12:54 pm

Re: "Viral" maths problem

Post by Fiona T »

Matt Morrison wrote: Sat Nov 21, 2020 1:24 pm Damn I must've been drunk. Saw you quoting that and I thought I must've made that post years ago, not last night.
Ha, me too - didn't notice the double not :D
User avatar
Matt Morrison
Post-apocalypse
Posts: 7822
Joined: Wed Oct 22, 2008 2:27 pm
Location: London
Contact:

Re: "Viral" maths problem

Post by Matt Morrison »

I do like to work with booleans.
Post Reply