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Andrew Schreder
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Aug-20-05, 11:07 PM (EST)
 
"Math puzzle"
 
   My soon to be 8th grade math teacher has posed this question: How is it possible that two-thirds of six is nine? I haven't a clue.Any help would be appreciated. Thanks!
Andrew


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alexb
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1631 posts
Aug-20-05, 11:13 PM (EST)
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1. "RE: Math puzzle"
In response to message #0
 
   >My soon to be 8th grade math teacher has posed this
>question: How is it possible that two-thirds of six is nine?

I do not like this question. 2/3 of 6 is 4; any other expected answer may be quite confusing.

>I haven't a clue.Any help would be appreciated.

I had this hunch. For division by an integer, it is common to say "n divides into m", for example, "7 divides into 21", or "7 divided into 21 gives 3."

The teacher might have meant that "2/3 divided into 6 gives 9" which is not quite the same as "two-thirds of six is nine", but sort of close.


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mr_homm
Member since May-22-05
Aug-21-05, 03:26 PM (EST)
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2. "RE: Math puzzle"
In response to message #0
 
   There are a couple of possibilities that I can think of, but they both go outside of pure mathematics. If you give the numbers specific meanings, such as using them to measure something physical, then the "units" of the measurement define what the numbers mean. For instance, your teacher may have in mind something like "2/3 of 6 yards is 9 feet" -- except that it isn't, of course. I can't come up with any units that make this work (one unit must be 4/9 of the other) so this is probably not what your teacher meant.

Another possibility is that the numbers are rates. For instance, if one person spends 6 hours per assignment on his homework and another person is 2/3 as fast, then that person will spend 9 hours per assignment. So you could say, "9 hours per assignment is 2/3 times as fast as 6 hours per assignment." I don't like this interpretation, because it really doesn't follow the rules of how people describe rates.

Either your teacher is trying to get you to notice that when numbers are used to describe things outside of mathematics, then the units or interpretations are important, or else your teacher has some silly mathematical joke in mind. If it's just a joke, I'll be disappointed, because math teachers who make this kind of joke in order to seem "interesting" or "funny" are not doing their students any good, and the jokes are usually too "lame" to make the students like the teacher either.

Good luck in your math class.

--Stuart Anderson


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Rohan Gujrati
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Aug-24-05, 03:26 PM (EST)
 
3. "RE: Math puzzle"
In response to message #0
 
   2/3 of 6=9.
6= SIX
SIX has 3 letters. Therefore, any 2 letters would make 2/3 of SIX.
Thus,taking the last 2 letters we have IX; which is Roman nine.
Hence two-thirds of six is nine.


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Ashish123
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Aug-26-05, 07:42 PM (EST)
 
4. "RE: Math puzzle"
In response to message #3
 
   Speaking on pure mathematical terms it is impossible to get 2/3of 6 as 9.

since 2/3is less than 1
hence anything multiplied by afraction would give a number less than original which in this case is 6.
so the answer should bo less than six


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