Maths Disagreement

[TulaOfDarkWater]

One person thinks the answer is 165 and the other thinks 67, who is right?

YABU - 165
YANBU - 67

Or what’s the answer if both are wrong?

38

I also got 38. You have to assume that the value of the clock is 1 for each hour, the value of the bananas is 1 per banana, and the value of the shape is 1 for each corner. Of course it could theoretically be different and a square is worth ten for no reason whatsoever, but you have to make the assumption that it’s possible to work it out from the information you’ve been given.
And then you do your multiplication before your addition.

@Lazypuppy

Bananas are different to. I get it as 2+3+3×10

2 o'clock + 3 bananas + 3 bananas × 2 shapes becomes 2 + 3 + 3 × 10.

With no brackets, I make that 80

According to BODMAS, I make that 35

This thread has just reminded me of why I HATED maths at school.

Beautiful language, understood in every country (according to Ms Jarvis anyway) - my arse!

This thread has just reminded me of why I HATED maths at school.

This isn't maths — it uses some of the conventions of maths but flouts other ones, in an attempt to confuse people.

It's maths combined with a logic problem.

If it was 'school maths' or part of some sort of test, it would need clearer instructions to show that it's not just about deducing that bananas = X but Bananas = xy.

Plus the illustration would need to be clearer because having people look at tiny pictures, mostly on a phone screen, where the detail is relevant, isn't sufficiently inclusive to people with less than perfect eyesight.

I also make it 2 + 3 + (3 x 11) = 38

Though given the way it's written, I don't think it's unreasonable to think it's (2+3+3)x11 = 88

Because Bodmas is a convention, not an infallible necessity of math, and no competent mathematician would write an equation like this without brackets or other more obvious indicator of precedence.

I really don't think of these as maths questions. They always seem more to do with observation skills to me.

@NumberTheory

I also make it 2 + 3 + (3 x 11) = 38

Though given the way it's written, I don't think it's unreasonable to think it's (2+3+3)x11 = 88

Because Bodmas is a convention, not an infallible necessity of math, and no competent mathematician would write an equation like this without brackets or other more obvious indicator of precedence.

I really don't think of these as maths questions. They always seem more to do with observation skills to me.

That's what I never understand about these questions. If there are no brackets, why assume brackets? I just don't get it.

@Gingernaut - you missed a facet from one of the shapes. There are 11 sides in total, not 10.

Though you could argue that each shape, regardless of number of sides = 5.

hivemindneeded

Because to do maths you have conventions. The 'rule' is multiplying comes before addition. You don't need the brackets because competent mathematicians know the rules and follow them. in theory brackets are superfluous.

However as seen on this thread, most people are not competent mathematicians. So anyone with half a brain writing things like this for 'the general public' would put brackets in to be on the safe side.

Similarly, I used to have 'discussions' with software developers over the need (in my opinion) to put in unnecessary (in their opinion) brackets at times to rally show they were being clear which order they wanted things to be done in a line of code. This was to help people maintaining the software later who might be less familiar with the code and therefore might accidentally screw it up.

It's the mathematical convention to carry out operations in a certain order when there are no brackets. If we don't "assume brackets" (i.e. use the right order) then we can't solve it because you have to do some things before other things to get a consistent answer.

@hivemindneeded

Though you could argue that each shape, regardless of number of sides = 5.

That's what I did. Still annoyed it was number of sides and got it wrong.

@TeenPlusCat - Thank you. When I first heard of BODMAS or BIDMAS, in my late forties/early fifties, I mentioned on a thread that it just wasn't taught at my school. Lots of people said, of course it was, it always has been. But judging by the vast number of people on here who instinctively add up from left to right then multiply the total, it seems it isn't properly taught - or wasn't - to a huge number of people. A lot of people have no idea of its existence.

I got 26

Only 3 bananas not 4 in the final row, and the clock shows 2 not 3, and you have 11 shape sides not 15. Then ensure you multiply.
2 + 3 + (3*11) = 38

I got 3+4+4+15

38

I was born in '67 and did BODMAS at primary level.

However except when explicitly testing BODMAS knowledge and to know that O comes before M for algebra I can see you can easily 'avoid' remembering it. Hence people claiming it wasn't taught to them. It might not have been taught with the acronym, but I think it is highly highly unlikely it wasn't taught at all.

3y^2 (3 y squared)

O then M : You have to know you square the y before multiplying it by 3.
So if y=5 then 3y^2 = 75, it does NOT equal 225.

@Lazypuppy

Bananas are different to. I get it as 2+3+3×10

This is what I got too. So I got 35 as an answer.

Now have 38 after realising the last shape is worth 11.

[quote hivemindneeded]@TeenPlusCat - Thank you. When I first heard of BODMAS or BIDMAS, in my late forties/early fifties, I mentioned on a thread that it just wasn't taught at my school. Lots of people said, of course it was, it always has been. But judging by the vast number of people on here who instinctively add up from left to right then multiply the total, it seems it isn't properly taught - or wasn't - to a huge number of people. A lot of people have no idea of its existence.[/quote]
In the UK schools, while it's been a part of most curriculums for a long time, far more emphasis has generally been placed on clear communication rather than relying on order of operations. US schools seem to like order of operations a lot more - I suspect, though have absolutely no proof, because of their reliance on multiple choice testing and the way it lends itself to "trick" questions to test if you know it.

Everyone instinctively applies BODMAS when calculating "6-½" (to get 5.5).

Logically it should not be different when written as "6-1÷2".

It's still 5.5 (not 2.5) because you still do the 1÷2 first.

Otherwise the result is dependent on presentation/formatting instead of the actual numbers and operations.

I just dont know how many people can be so unaware of primary level maths.

If you have this equation:

2 + 3 + 3 × Y

When solving it, do you make it this,:

2Y + 3Y + 3Y

Or this,

2 + 3 + 3Y.

You make it the latter. You dont times every number by Y. You only join it with the number it was being multiplied by. Because there are 3 Ys.

The only time you would times Y by everything is if the equation was,

Y(2+3+3).

In that case, each number is multiplied by Y.

Replacing Y with a number doesnt change this.

So 2 + 3 + 3Y
Is the same as 2 + 3 + 3 × 11

And you do the 3 × 11 first to get 33. Then add the rest.

The fact that people continue to post totally nonsense after this has been explained over and over makes it very obvious that even if they were taught it properly, they still couldn't do it so would rather pretend that it is "new" maths.

@NumberTheory

You dont need bracket in this.
You only need them if you are NOT competent. We didnt have brackets for simple things like this in high school, nor were they added when I was at uni and working through various equations because they are not needed.