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jatill
Daedalian Member
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Posted: Tue Oct 05, 2010 8:03 pm Post subject: 1 |
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1024 is a "powerful number" because 1024 is
1) expressed in simplest form (i.e. no leading 0's, etc),
2) can be represented as x^y, where x and y are integers, and
3) the number of characters in the number 1024 is the same as are the number of characters in x^y (i.e. 2^10 => 4 characters).
a) What is the highest powerful number?
b) What is the lowest powerful number?
c) What is the powerful number closest to 0? |
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Zag
Tired of his old title
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Posted: Tue Oct 05, 2010 8:19 pm Post subject: 2 |
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For the lowest, how about: 4^2 or 2^4 = 16
Of course, you probably should have said the lowest in absolute value. There are negative powerful numbers, I'm sure. (-27, for instance = (-3)^3, which, I think, is the largest negative powerful number.) |
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bonanova
Daedalian Member
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Posted: Tue Oct 05, 2010 11:52 pm Post subject: 3 |
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Zag, does your LPN candidate obey (3)? Maybe I don't understand (3). _________________
Vidi, vici, veni.
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Trojan Horse
Daedalian Member
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Posted: Wed Oct 06, 2010 12:01 am Post subject: 4 |
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| For the one closest to 0: .000001=1000^-2 (with 7 characters in each) is the best I've been able to come up with so far. (Assuming that's not cheating.) |
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Zag
Tired of his old title
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Posted: Wed Oct 06, 2010 1:15 am Post subject: 5 |
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| Oh. I didn't read the rule carefully enough to realize we were supposed to count the caret. Of course, when you write it in normal math style, there isn't one. |
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Jake2*
Guest
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Posted: Wed Oct 06, 2010 11:20 am Post subject: 6 |
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| For the largest, I get 99856 (316^2). |
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jatill
Daedalian Member
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Posted: Wed Oct 06, 2010 12:04 pm Post subject: 7 |
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| Zag wrote: |
For the lowest, how about: 4^2 or 2^4 = 16
Of course, you probably should have said the lowest in absolute value. There are negative powerful numbers, I'm sure. (-27, for instance = (-3)^3, which, I think, is the largest negative powerful number.) |
By lowest I did mean most negative, otherwise it would have been the same as (c).
Edit: (a) and (b) are both unsolved. I don't actually know the answer for (c), but don't forget that .25 and 1/4 are valid numbers |
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Trojan Horse
Daedalian Member
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Posted: Wed Oct 06, 2010 4:38 pm Post subject: 8 |
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| jatill wrote: |
| Edit: (a) and (b) are both unsolved. |
Did you miss Jake2's answer, jatill? I'm going to defend him, and say that he got the best possible answer for (a). (Assuming that, in the expression x^y, both x and y must be written in "standard form", with no leading zeros.)
I think I could write out a full proof that Jake2 got the best possible answer. (No time to do it right now, though.) |
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jatill
Daedalian Member
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Posted: Wed Oct 06, 2010 5:01 pm Post subject: 9 |
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| Trojan Horse wrote: |
| jatill wrote: |
| Edit: (a) and (b) are both unsolved. |
Did you miss Jake2's answer, jatill? |
Nope, but I'm pretty sure there's a better one. |
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Death Mage
Raving Lunatic
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Posted: Wed Oct 06, 2010 5:23 pm Post subject: 10 |
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| Quote: |
| For the one closest to 0: .000001=1000^-2 (with 7 characters in each) is the best I've been able to come up with so far. (Assuming that's not cheating.) |
Do decimal commas count?
-.00000001 = -10,000^-2 _________________ * These senseless ramblings brought to you by Insanity™. If you just can't figure the dang thing out, it must be Insanity™.
[YOUR AD HERE!] |
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jatill
Daedalian Member
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Posted: Wed Oct 06, 2010 5:36 pm Post subject: 11 |
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| Death Mage wrote: |
| Quote: |
| For the one closest to 0: .000001=1000^-2 (with 7 characters in each) is the best I've been able to come up with so far. (Assuming that's not cheating.) |
Do decimal commas count?
-.00000001 = -10,000^-2 |
Commas don't count. The only characters that are legal would be 0-9, -, ., and / (for fractions). |
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Trojan Horse
Daedalian Member
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Posted: Wed Oct 06, 2010 8:20 pm Post subject: 12 |
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Oh, duh... [998001=(-999)^2]
I'm assuming, based on the last comment, that parentheses don't count. If they did count, we could do this: [9999800001=(-99999)^2] |
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jatill
Daedalian Member
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Posted: Thu Oct 07, 2010 12:07 pm Post subject: 13 |
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| Trojan Horse wrote: |
Oh, duh... [998001=(-999)^2]
I'm assuming, based on the last comment, that parentheses don't count. If they did count, we could do this: [9999800001=(-99999)^2] |
You're on the right track, but you can do better. And you are right in assuming that parens are illegal. |
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Trojan Horse
Daedalian Member
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Posted: Thu Oct 07, 2010 8:17 pm Post subject: 14 |
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*sigh*
Probably still not the best, but [9998244=-3162^2] works.
I await your reply that there is still a better answer out there. |
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jatill
Daedalian Member
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Posted: Fri Oct 08, 2010 10:20 pm Post subject: 15 |
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You finally nailed part (a)  |
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