Math question

Water Cooler
#1

Who can solve this equation?

230 - 220 x 0.5 = ???

Believe it or not, the answer is 5! Prove me wrong.

#2

please excuse my dear aunt sally! shes slow!

#3

What Nerdy is saying is, the order of operations would have multiplication happening before subtraction, so the answer should be 120.

What context am I missing, Greenie?

EDIT: Before responses arrive with the idea that PEMDAS is a heuristic only, and that it leaves out crucial ordering detail, let me say that the equation provided here by Greenie creates no conflict such as whether addition or subtraction should come first. The case is multiplication versus subtraction here, and multiplication will take precedent over subtraction in the absence of parenthetical notation.

#4

Uh… yeah dude, the answer is not 5. What DOW said above is right. I’m sure S2K will corroborate shortly. Incredible how many of these you see posted on social media platforms and how many people get it wrong. I get people not remembering 4th grade math or whatever, but I use PEMDAS once in a while in spreadsheets to this day.

#5

Once met a college student who didn’t know how to calculate the average of 4 values. Now that’s incredible. I bet she would have a hard time with Greenie’s equation as well.

#6

Needs more brackets/parentheses, I tellz ya!!! :nerd_face:

Whatever happened with “asynchronous”? You left us hanging! :cry:

#7

That’s an awesome question!

It turns out that it doesn’t!

I love subtlety!

#8

Not context!

Subtlety!

PEMDAS holds!

#9

When teaching a cash flow analysis class for the CFP program I had to use a textbook written by one of the professors at the university where I was teaching. His formula for the mean of a sample was:

\bar X = \frac{\sum_{i=1}^n X_i}{n - 1}

(Was your acquaintance possibly studying for the CFP?)

#10

Absolutely correct!

Nevertheless, Greenie’s right!

#11

Had to look it up. Pretty clever.

#12

its a factorial. 5! = 120

#13

OK everybody sit down for this one:

I got out my BAII and set it to Chain calculation under the Format menu. It turns out 230 - 220 x .5 is indeed 5!! Come at me, haytaz!!! :upside_down_face:

#14

Um . . . 5!! ≈ 6.68950291344913×10^{198}

I’m pretty sure that that’s not the correct answer.

#16

Ah I see what you did there! It’s a factorial notation and not conveyance of disbelief or excitement! How clever! Ha ha ha…eh…

#17

Shouldn’t you have taken out your red pen and pointed out that Greenie should have included a period after 5!? Come on, S2K, you’re falling off…

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#18

825×825 142 KB

#19

Ding ding ding! Correctamundo!!!

#20

5 factorial

#21

For any two numbers a and b where a=2n!-2n and b=2n!-4n, you can shock your casual social acquaintances by claiming that a-b/2=n! and sip on your fine scotch as you watch in a quiet amusement when they try to convince you that you really mean (a-b)/2=n since your claim does not follow the order of operations. By choosing a different n every time, you can vary a and b accordingly and deliver the same punchline with repeated success, ensuring that the joke never gets out of style and you remain the life of the party.

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