View Full Version : I got this wrong

Loose rivets

7th Apr 2018, 00:22

Can't they do sums in Italy, thinks I, Hmm . . . on second thoughts I realised I hadn't got it right.

Perhaps we should have a, Keep Old Brains Alive thread.

WingNut60

7th Apr 2018, 00:44

Can't they do sums in Italy, thinks I, Hmm . . . on second thoughts I realised I hadn't got it right.

Perhaps we should have a, Keep Old Brains Alive thread.

I'll take a stab --- 27?

Ascend Charlie

7th Apr 2018, 02:35

2 + (20 x 5) = 102

But why would you cross a red flower with a blue flower?? It will end up a yucky brown.

WingNut60

7th Apr 2018, 02:39

I'll take a stab --- 27?

Oops - that was aging eyesight (cognition) not stupidity.

Or that's my story.

1 Red flower = 20

1 Blue flower = 5

2 Yellow flowers = 2, therefore;

1 Yellow flower = 1

1+20x5=1+(20x5)=1+100=101

ExSp33db1rd

7th Apr 2018, 05:05

How about 21 x 5 = 105 ? Where did the () come into it ?

How about 21 x 5 = 105 ? Where did the () come into it ?

multiplication is granted a higher precedence than addition, and it has been this way since the introduction of modern algebraic notation. Thus, the expression 2 + 3 × 4 is interpreted to have the value 2 + (3 × 4) = 14

https://en.m.wikipedia.org/wiki/Order_of_operations

3 x red = 60, so 60/3 = 20 for red.

20 + 2 x blue = 30, so 30 - 20 = 10, and 10/2 = 5 for blue.

5 - 2 x yellow = 3, so 2 yellow = 2, and 2 yellow/2 = 1 for yellow.

1 + 20 x 5 = 101 (You have to do the 20 x 5 operation first, before adding its product to the 1. Using brackets shows the order of operations, multiplication before addition. 20 x 5 + 1 = 101, or should that yield 120? It can't be that swapping positions yields a different result, can it?)

It's not a math problem as such (if you assume that everyone can do the four basic operations), more just a visual trick because one tends to overlook that there are two yellow flowers in the third problem, not one, and multiplication in the final one where until then it had been addition, subtraction, and (not shown) division. Everywhere else it's single flowers, but two bunched in just that one problem, and one "x" where you (if you are careless like me) expect to see a "+".

It's like that "Paris in the the springtime," problem, in a way. Cute!

3 x red = 60, so 60/3 = 20 for red

20 + 2 x blue = 30, so 30 - 20 = 10, and 10/2 = 5 for blue

5 - 2 x yellow = 3, so 2 yellow = 2 and 1 yellow = 1

1 + 20 + 5 = 26

It's not a math problem as such (if you assume that everyone can do the four basic operations), just a visual trick becaause one tends to overlook that there are two yellow flowers in the third problem, not one. Everywhere else it's single flowers, but two bunched in just that one problem.

It's like that "Paris in the the springtime," problem.

Look at it again, it’s not 1 + 20 + 5, it’s 1 + 20 X 5

Pontius Navigator

7th Apr 2018, 07:30

Hempy, or BODMAS for those without wiki or computers :)

Hempy, or BODMAS for those without wiki or computers :)

Well I’m assuming most people here have a computer (or at least an internet capable device) since PPRuNe is indeed a website, as is wikipedia. I’m actually a bit shocked tbh, because other than the visual trip-ups with the yellow flowers and the multiplication added in the last line I would have thought most people could have derived the correct answer in their head inside 2 seconds flat. I learned the order of operations in primary school, although I’ve only recently learned that it’s taught these days as a mnemonic (BODMAS/PEMDAS). I couldn’t tell you what the mnemonics stand for though, and since I already know the order of operations anyway I don’t particularly care :ok:

artschool

7th Apr 2018, 08:05

the blue flower at the end is different, it has less petals.

the blue flower at the end is different, it has less petals.

^^ excellent point! I change my answer to 81!! :}

True - the early blue flowers worth 5 have 5 petals, the last only has 4. So it wworth only 4?

I’ll say 84

1+20x4=84

Again, the order of operations is wrong here. 1+20x4=1+(20x4)=1+80=81.

Again, the order of operations is wrong here. 1+20x4=1+(20x4)=1+80=81.

But 1+20=21x4=84

eckhard

7th Apr 2018, 10:02

Well as an arithmetician I flunked it but as a grammarian I have to point out that the blue flower has fewer petals and that BODMAS is a mnemonic.

Back into my box.

Tankertrashnav

7th Apr 2018, 10:16

I see these things on Facebook all the time. I usually scroll past quickly and look for some amusing kittens.

Much more relaxing!

BODMAS is all well and good, but was the person who decided we should spell mnemonic that way dyslexic?

Well as an arithmetician I flunked it but as a grammarian I have to point out that the blue flower has fewer petals and that BODMAS is a mnemonic.

Back into my box.

Mea culpa. Spelling has never been my strong point! :{

But 1+20=21x4=84

You don’t read arithmetic left to right like you read a sentence (in English anyway). The multiplication comes before the addition.

ZOOKER

7th Apr 2018, 10:24

I make it 82, if the last flower is 1 petal short.

(20 x 4) + 2

Or as it is written 2 + 20 x 4 = 88

Fareastdriver

7th Apr 2018, 10:43

2+(20x4)=82?

goudie

7th Apr 2018, 11:06

You’re all wrong. It’s 42.

I make it 82, if the last flower is 1 petal short.

(20 x 4) + 2

Or as it is written 2 + 20 x 4 = 88

2+(20x4)=82?

We are assuming that if a blue flower with five petals is worth 5 then a blue flower with four petals is worth 4, and that if two yellow flowers equals 2 then one yellow flower equals 1.

Based on those assumptions the last line reads;

1 + 20 x 4

Following the rules of mathematical order of operations, the multiplication is completed before the addition;

1 + 20 x 4 =

1 + 80 =

81

ZOOKER

7th Apr 2018, 11:16

Apologies Hempy,

I've only just noticed that there are 2 yellow flowers in line 3!

Fareastdriver

7th Apr 2018, 11:33

I've only just noticed that there are 2 yellow flowers in line 3!

Same here.

No wonder that you can never fix a Fiat.

WingNut60

7th Apr 2018, 12:02

..... (BODMAS/PEMDAS). I couldn’t tell you what the mnemonics stand for though....... :ok:

From junior high school 52 years ago : "brackets of division multiplication addition subtraction"

And I'll now go with 81.

Loose rivets

7th Apr 2018, 12:05

Surprising just how the brain can be fooled into passing on duff information from the visual cortex. The back of the noggin' does a wondrous job of visual analysis but then the frontal lobes start to reason. We can be fooled into actually seeing what that region thinks should be there. See, Blindness denial.

Oh for the brain of our original design, as in my The Perfect Code. If it had been allowed to evolve to the full blueprint's specification, we'd all be hyper-geniuses. But then, I made that story up. Having said that, and while I don't believe anything without question, I really have a gut feeling that the mechanism of evolution could well have been designed to spray out into countless species in order to hide away from planetary destruction etc., and hasn't had time to make it all the way back to perfection.

My brain was quite willing to accept things should be there. :ugh:

.

.

.

Sallyann1234

7th Apr 2018, 12:11

From junior high school 52 years ago : "brackets of division multiplication addition subtraction"

And I'll now go with 81.

Brackets orders division multiplication addition subtraction

cattletruck

7th Apr 2018, 12:15

Yes, I'm looking at what everyone else is looking at, but my brains asks is there a discount for buying flowers in bulk?

WingNut60

7th Apr 2018, 12:19

Brackets orders division multiplication addition subtraction

A different high school, Sally.

And maybe a different era.

It’s down to a couple of non existant brackets Petal. No need to get upset. I AM RIGH.T

Gertrude the Wombat

7th Apr 2018, 22:58

A different high school, Sally.

And maybe a different era.

Look, there are some (computer) languages in which the operator priorities for some of the more exotic operators may not be quite what you'd expect, but nothing in this puzzle is remotely that weird, it's all primary school stuff. (And any sane coding standard says "if you have to think about the operator priorities, FFS put the brackets in so that the next person doesn't have to".)

WingNut60

7th Apr 2018, 23:57

Look, there are some (computer) languages in which the operator priorities for some of the more exotic operators may not be quite what you'd expect, but nothing in this puzzle is remotely that weird, it's all primary school stuff. (And any sane coding standard says "if you have to think about the operator priorities, FFS put the brackets in so that the next person doesn't have to".)

Bear in mind that this is a puzzle, designed to confuse.

Omitting the brackets was just part of the puzzle.

My mistakes were a) missing the two flowers, b) missing the multiplication sign.

I've gone along with : 4 petals = 4/5 * 5, but that could just as easily mean something else or nothing; like a drawing mistake or 4-petalled blue flowers could a different argument altogether.

42, of course. What was I thinking of?

How many roads must a man walk down?

As he's on his way the man comes to a y-junction where sits a native in native dress. The man has been warned that these natives come in pairs, so that you meet always one of a pair of identical twins, one of whom always tells the truth, while the other one always lies.

"... both that morning equally lay

In leaves no step had trodden black" so what question should the man ask the native in order to know which road to leave not taken?

Alice: Would you tell me, please, which way I ought to go from here?

The Cheshire Cat: That depends a good deal on where you want to get to.

Alice: I don't much care where.

The Cheshire Cat: Then it doesn't much matter which way you go.

Alice: ...So long as I get somewhere.

The Cheshire Cat: Oh, you're sure to do that, if only you walk long enough.

ExSp33db1rd

8th Apr 2018, 09:48

it has been this way since the introduction of modern algebraic notation.

Never was any good at Algebra, and now Mrs ExS reckons I'm financially dyslexic.

At least I can just sit back and watch then ! ( see my previous comments on the idiocy of banks, maybe they're not ? )

Mea culpa. Spelling has never been my strong point! :{

You don’t read arithmetic left to right like you read a sentence (in English anyway). The multiplication comes before the addition.

Thanks a bunch😜

Mike6567

8th Apr 2018, 19:37

ʇɔǝɹɹoɔ ʎɐʍlɐ sı ʎdɯǝH ʞuıɥʇ I

llondel

9th Apr 2018, 03:25

ʇɔǝɹɹoɔ ʎɐʍlɐ sı ʎdɯǝH ʞuıɥʇ I

The 'l' in 'always' is misaligned. As are the 'I' and 'H'. :8

so what question should the man ask the native in order to know which road to leave not taken?"If I were to ask your twin brother which road not to take, what would he say?"

ʇɔǝɹɹoɔ ʎɐʍlɐ sı ʎdɯǝH ʞuıɥʇ I

ǝɟᴉʍ ʎɯ oʇ ʇɐɥʇ llǝʇ ǝsɐǝlԀ

Hokulea

9th Apr 2018, 11:43

How are those living relatively close to the equator supposed to write? Sideways or vertically? I guess writing at an angle might work if the forum software allowed it.

How are those living relatively close to the equator supposed to write? Sideways or vertically? I guess writing at an angle might work if the forum software allowed it.

⊣ェᗆ⊣ᔕ ᗆ ⊣o⊂ᘏェ oᴝጠ!

Hokulea

9th Apr 2018, 12:24

It's tough, but that's a damn good attempt!