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You are wrong, the teacher is right.
The order of precedence in mathematical operations is (mnemonic PEMDAS):
Parentheses
Exponentiation
Multiplication & Division
Addition & Subtraction
If two operations have the same precedence, they are evaluated from left to right. Your problem may be rewritten as 230 - (220 x 0.5), the answer to which is obviously not 5.
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
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3! - 1
I think you'll find
It's curious - nearly everyone I know was taught BODMAS - its the same as PEDMAS, but B=Brackets, O="of". PEDMAS is probably better. Also the great Indian chief "SOH-CAH-TOA". I wonder if they still teach the latter in schools.
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I hadn't heard of PEDMAS before; I'm guessing it's some kind of Hollywood holiday.
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Rather than the Indian chief, we were taught the great Welsh anthem:
Sons of Harlech
Come and Harken
To our Anthem
A geographic thing, I suppose. We were 50 miles from Wales but several thousand from the Indians.
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You write "the answer to which is obviously not 5". Nobody ever said that. The OP sais that he "announced that the answer was 5!". Do you see the difference? The exclamation mark. The answer is 5! (five factorial) and 5!=5*4*3*2*1=120 so 5! is the correct answer
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Please don't repost if your comment does not appear immediately: both of these went to moderation and required a human being to review them for publication. In order to prevent you being kicked off as a spammer, both had to be accepted, and then I have to clean up the spares. Have a little patience, please!
I've deleted the other version.
"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
"Common sense is so rare these days, it should be classified as a super power" - Random T-shirt
AntiTwitter: @DalekDave is now a follower!
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Note that he said "5!", not "5". He might have given it away too big a clue if he had ended his sentence properly with a period like "...I said the answer is 5!."
Good nerdy riddle.
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Daniel Pfeffer wrote: PEMDAS
I was taught "Please excuse my dear aunt sally".
Or
"Pizza everyone!, my diet already started."
Brent
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He is not wrong. You just didn't see the entire answer in your brain. The exclamation point is there for a reason.
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Have you write 5! as answer, or it is only for us as an expression of your frustration?
"The only place where Success comes before Work is in the dictionary." Vidal Sassoon, 1928 - 2012
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See my hint to another responder.
Brent
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dbrenth wrote: the answer was 5! five factorial. Unless you were yelling at them.
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dbrenth wrote: Can you please explain it to him?
Dear Teacher,
dbrenth is a cocky little so and so, who needs to be taken down a peg or two.
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And marked down for not completing the solution.
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You teacher was right, and told you the correct result was actually 76 .
Could you please tell us why?
"In testa che avete, Signor di Ceprano?"
-- Rigoletto
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I thought the answer was 78.
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42.
"In testa che avete, Signor di Ceprano?"
-- Rigoletto
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Octal
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.
-- 6079 Smith W.
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Bravo!
"In testa che avete, Signor di Ceprano?"
-- Rigoletto
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If you solve it left-to-right, ignoring precedence order, then the answer is 5. An old TI calculator would give you that answer. Today's windows calculator will not: it says 120 because the multiplication is done first.
"They have a consciousness, they have a life, they have a soul! Damn you! Let the rabbits wear glasses! Save our brothers! Can I get an amen?"
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"5!" = 120
It's a clever nerdy riddle. I like it!
I wonder if I'd have been hassled after math class for giving such an answer?
and I just noticed that Microsoft Excel doesn't recognize factorials.
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And today you learn that nobody likes a smartarse ...
"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
"Common sense is so rare these days, it should be classified as a super power" - Random T-shirt
AntiTwitter: @DalekDave is now a follower!
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OriginalGriff wrote: nobody likes a smartarse
Maybe he should brace himself for the reactions to come?
If you can't laugh at yourself - ask me and I will do it for you.
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