A “simple” 3rd grade problem
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A “simple” 3rd grade problem
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Re: A “simple” 3rd grade problem
#2[deleted]
Re: A “simple” 3rd grade problem
#3The story is a wonderful illustration that the human brain is not perfect. It seems that most people when first reading the math problem get it wrong. Our brain is designed to first jump to conclusions before seriously thinking about the problem. The human mind may be the highest form of intelligence on the planet, but that does not mean that there are not serious design flaws. The human brain was born out of a process of Evolution, and is designed to function in a natural setting. Perhaps in a distant future, when humanity has created true A.I., it will be possible to observe just how biased and illogical the human mind really is by comparing it to artificial intelligence.
Re: A “simple” 3rd grade problem
#4It's more a logic question than a math one. The confusion spawns from the fact that the three numbers present in the question are 10, 2, and 3 (so the thought process would be 2 = 10 min so 1 = 5 min, thus 3 = 15 min).
But 2 represents the final state, though requires only 1 action (cut). And the required answer (time spent) is related to the number of actions, not the final state.
This reminds me of the water lily problem: a water lily doubles in size every day. It takes 30 days to cover the whole pond. How many days does it take for the water lily to cover half the pond? (Answer: 29, not 15).
Re: A “simple” 3rd grade problem
#5the student is right because it states "into 2 pieces" which means you do one cut to an object and you now have 2 objects. this is total number of pieces = number of cuts + 1 from the beginning.
probably the person who graded the question assumed that you are cutting chunks from an object, like slicing a bread. for every cut(except the last one) you get one new object, so every cut is +1 new object. if you slice the whole thing and the remaining object can be +1 piece, just like in the first situation, if you consider the last piece equal to the pieces you cut.
so, +1 to the student :)
Re: A “simple” 3rd grade problem
#6Who was it that said the biggest problem in programming is concurrency and off by one errors?
Re: A “simple” 3rd grade problem
#7I would've arrived at the teacher's solution, but the question allows different interpretations and both answers are correct assuming different interpretations.
The correct answer would be "I do not know, this problem is under-specified."
Re: A “simple” 3rd grade problem
#8I would've arrived at the teacher's solution, but the question allows different interpretations and both answers are correct assuming different interpretations. The correct answer would be "I do not know, this problem is under-specified."
Can you explain why you think it has two correct interpretations?
I obviously thought 15 min when I first read it and my brain didn't want to accept any other solution until I read the post below where it said 20 min and explained it as 2 pieces = 1 cut = 10 min, 3 pieces = 2 cuts = 20 min.
And now I can't see why my first thought was correct. Did you come up with some good rationale as to why it should be 15 min or other?
Re: A “simple” 3rd grade problem
#9Who was it that said the biggest problem in programming is concurrency and off by one errors?
Or clear communication and understanding of the specifications?
Seems impossible for anyone to interpret it differently than the student did, but from the comments it's clearly easy for people to extract ambiguity from what appears to be a simple, straightforward specification.
Re: A “simple” 3rd grade problem
#10I would've arrived at the teacher's solution, but the question allows different interpretations and both answers are correct assuming different interpretations. The correct answer would be "I do not know, this problem is under-specified."
> The correct answer would be "I do not know, this problem is under-specified."
In that case, I'd write my assumptions about the problem and show how I arrived at the solution. If the teacher still says it's wrong, I probably won't bother arguing - I don't waste my time arguing with morons.