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| Author |
Message |
abc
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Math Puzzle
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Apr 11 22:35 UTC 2000 |
(my officemate received the following via e-mail; thought I'd post it here
in case anyone is interested)
Make each equation equal to 10 using the following symbols:
+, -, x, /, ., ^, sqrt, and ( ). The digits MUST be kept in the
order given, and each number can only be used once. Good luck!
a) 12 = 10
b) 123 = 10
c) 1234 = 10
d) 12345 = 10
e) 123456 = 10
f) 1234567 = 10
g) 12345678 = 10
h) 123456789 = 10
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| 17 responses total. |
carson
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response 1 of 17:
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Apr 12 00:04 UTC 2000 |
(linked to games)
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remmers
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response 2 of 17:
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Apr 12 00:18 UTC 2000 |
a) sqrt(.1^(-2)) = 10
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jp2
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response 3 of 17:
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Apr 12 00:43 UTC 2000 |
This response has been erased.
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jp2
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response 4 of 17:
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Apr 12 00:45 UTC 2000 |
This response has been erased.
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mdw
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response 5 of 17:
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Apr 12 01:20 UTC 2000 |
c can also be done with just +. 1+2+3+4. I'm not sure there's any
other solution using just one character in such a simple pattern.
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aruba
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response 6 of 17:
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Apr 12 03:27 UTC 2000 |
d) 12-3-4+5 = 10
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jp2
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response 7 of 17:
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Apr 12 03:30 UTC 2000 |
This response has been erased.
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jp2
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response 8 of 17:
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Apr 12 03:35 UTC 2000 |
This response has been erased.
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jp2
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response 9 of 17:
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Apr 12 03:37 UTC 2000 |
This response has been erased.
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jp2
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response 10 of 17:
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Apr 12 03:42 UTC 2000 |
This response has been erased.
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rcurl
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response 11 of 17:
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Apr 12 04:54 UTC 2000 |
123-45-67+8-9
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remmers
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response 12 of 17:
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Apr 12 11:55 UTC 2000 |
So except for (a) and (b), they can all be done using only + and -.
It becomes a more challenging problem if we define a solution as
"better" if it uses more of the specified symbols. By this measure,
#4 is the best solution so far, since it uses five of them: sqrt, .,
-, *, and ^.
(I'm not counting multiple uses of the same symbol. Nor am I
counting parentheses, since they're essentially "free".)
So, how 'bout some better solutions?
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rcurl
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response 13 of 17:
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Apr 12 17:30 UTC 2000 |
I don't know about this making up 'rules' about what is 'better'as you
go...... #11 was the first one using a three digit number. Try doing it
using a four digit number. Also, I think it is 'better' using the *least*
number of symbols: the Thoreau principle. By this test, #6 is best. Your
criterion is the IRS principle.
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remmers
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response 14 of 17:
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Apr 12 17:38 UTC 2000 |
Whatever. I'm just suggesting a way to make the puzzle more
challenging. In the future, I'll be sure to use my powers of
prescience and make any suggestions for improvement at least
a week before a puzzle is posted.
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darkskyz
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response 15 of 17:
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Apr 12 22:01 UTC 2000 |
i'm not sure if this solution is valid, but i thought i'd suggest it anyways:
1^2=1^0
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rcurl
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response 16 of 17:
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Apr 12 22:54 UTC 2000 |
That's the solution to *some* math puzzle - but which one?
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darkskyz
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response 17 of 17:
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Apr 13 21:50 UTC 2000 |
ar. that's a, but i just looked up and realized that the rval has to be 10...
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