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A fake Facebook event disguised as a math problem has been one of its top posts for 6 months
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The issue normally with these "trick" questions is the ambiguous nature of that division sign (not so much a problem here) or people not knowing to just go left to right when all operators are of the same priority. A common mistake is to think division is prioritised above multiplication, when it actually has the same priority. Someone should have included some parenthesis in PEDMAS aka. PE(DM)(AS) ๐
The same priority operations can be done in any order without affecting the result, that's why they can be same priority and don't need an explicit order.
6 ร 4 รท 2 ร 3 รท 9 evaluates the same regardless of order. Can you provide a counter example?
So let's try out some different prioritization systems.
Left to right:
Right to left:
Multiplication first:
Here the path divides again, we can do the left division or right division first.
And finally division first:
It's ambiguous which one of these is correct. Hence the best method we have for "correct" is left to right.
I stand corrected
No, you weren't. Most of their answers were wrong. You were right. See my reply. 4 is the only correct answer, and if you don't get 4 then you did something wrong, as they did repeatedly (kept adding brackets and thus changing the Associativity).