This is so easy to get right...or wrong...

[Deleted member 26715]

I like that one - although the convention isn't usually to overlap powers. And the maths is much more difficult.

From the previous line we know y = 5
5 + z to the power of z + z to the power of z = 9
z to the power of z + z to the power of z = 9 - 5
z to the power of z + z to the power of z = 4
z to the power of z = 4 / 2
z to the power of z = 2
z = square root of 2 = 1.41421356237
Bottom line =
5 + 1.41421356237 x 10 =
Using Bodmas
5 + 14.1421356237 = 19.1421356237

 

[srw]

From the previous line we know y = 5
5 + z to the power of z + z to the power of z = 9
z to the power of z + z to the power of z = 9 - 5
z to the power of z + z to the power of z = 4
z to the power of z = 4 / 2
z to the power of z = 2
z = square root of 2 = 1.41421356237
Bottom line =
5 + 1.41421356237 x 10 =
Using Bodmas
5 + 14.1421356237 = 19.1421356237

Damn. I was thinking I'd have to use logarithms.

 

[Oxo]

Slide rule!

 

[Deleted member 26715]

Damn. I was thinking I'd have to use logarithms.

Okay I admit defeat, I have used them but getting near 40 years ago, not sure where or how to start with them these days. But BODMAS has always stood me in good stead, although I got confused the other day when youngsters (I presume) started referring to it as BIDMAS

 

[Flying_Monkey]

Eh? I had thought that having got over my initial failures - to distinguish the one chips/two chips, and to spot the x rather than + symbol - followed up by taking on board the requirement to multiply before adding (don't know why, but I'm a trusting soul) - I arrived at what I'd assumed was the correct answer: to whit, 15 - ie, 5 + (1 x 10). Now you're telling me it's 25? Now what have I got wrong?

You haven't got anything wrong. Unless we are going to start making very different assumptions, here, each item is just like a letter in conventional algebra.

The first two lines are easy. It's clear that 'Shake' = 10 and 'burger' = 5. The two 'tricks' in the puzzle are:

1. there are 2 lots of 2 'fries' the first time we encounter them (giving a total of 4), and only one the second time. Thus line 3 can be rewritten as 5 + (2 x 1) + (2 x 1) = 9. So 'fries' = 1.

2. there is a multiplication in the final statement, and the 'order of operations' in conventional mathematics, in the absence or brackets etc., means that you do multiplication and division before addition and subtraction, so the final line can be rewritten as (1 x 10) + 5. So the final result is 15.

I don't see what's complicated about this.

 

[Flying_Monkey]

I think this is the bit that catches people out after feeling all smug about getting 'order of operations correct'

The trick is actually more of a test of visual accuity or attention rather than mathematics. If it was written in letters, it wouldn't be as 'difficult'.

 

[User482]

I don't see what's complicated about this.

At the risk of taking this too seriously...

It's complicated because the answer depends on the application of a conventional order of operations (rather than some fundamental truth) which is ambiguous in the way it is taught, and is not universally applied. For example, BODMAS implies that addition takes precedence over subtraction, and is not universally applied in calculators or spreadsheets.

 

[Profpointy]

At the risk of taking this too seriously...

It's complicated because the answer depends on the application of a conventional order of operations (rather than some fundamental truth) which is ambiguous in the way it is taught, and is not universally applied. For example, BODMAS implies that addition takes precedence over subtraction, and is not universally applied in calculators or spreadsheets.

order of addition and subtraction doesn't matter does it - assuming I've not had an embarassing brain fade of course.

The challenge is to surmise the meaning of two punnets of chips. Is it chips + chips or chips * chips or chips to the power of chips even. And I didn't spot there were two punnets either

 

[User482]

order of addition and subtraction doesn't matter does it - assuming I've not had an embarassing brain fade of course.

The challenge is to surmise the meaning of two punnets of chips. Is it chips + chips or chips * chips or chips to the power of chips even. And I didn't spot there were two punnets either

My point is that a literal application of BODMAS would give 7-2+4=1. As you say, there is actually no precedence so we would naturally calculate left to right giving 9. It's perhaps then not so surprising that people are tripped up when multiplication is introduced...

By the way, have you tried entering -4^2 into Excel?

 

[slowmotion]

I had never heard of BODMAS until last night. Does that explain my D grade?

 

[slowmotion]

In India they use PEMDAS. Wouldn't be easier to lob in a few brackets to avoid confusion?
http://blog.aggregatedintelligence.com/2009/01/bodmas-or-pemdas-it-is-elementary.html

 

[nickyboy]

order of addition and subtraction doesn't matter does it - assuming I've not had an embarassing brain fade of course.

The challenge is to surmise the meaning of two punnets of chips. Is it chips + chips or chips * chips or chips to the power of chips even. And I didn't spot there were two punnets either

Chips...punnets? Maybe where you come from that's acceptable nomenclature, but not around here it ain't

 

[Oxo]

I had never heard of BODMAS until last night. Does that explain my D grade?

No, there is simply no explanation for that. It just is what it is.

 

[PhilDawson8270]

In India they use PEMDAS. Wouldn't be easier to lob in a few brackets to avoid confusion?
http://blog.aggregatedintelligence.com/2009/01/bodmas-or-pemdas-it-is-elementary.html

Or BIDMAS?

Brackets Indices Division Multiplication Addition Subtraction

 

[Profpointy]

Chips...punnets? Maybe where you come from that's acceptable nomenclature, but not around here it ain't

What's the posh term for punnet or chips then? An overseas guy asked me to explain "dinner time" to him and how it differed from lunch. He was confused when I explained that if you had "dinner" in the evening rather than at dinner time it became "tea"