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Post by Ark on Mar 6, 2006 16:28:10 GMT -5
Perfect, me gets one credit. NExt problem.
from the same site, so it's naruto themed.
You're at the weapons shop buying new shurikens as you used all of them in the last annoying mission that involved scrolls and explosive tags... You asked for 20 shurikens but the dishonest shopkeeper gave you a fake one hidden in the 19 real ones. The fake shuriken looks and feels exactly the same as the real ones, except for a slight weight difference. You've been warned by the jounins about this shopkeeper and they told you a way to find out which shuriken is fake by using a balancing scale. However, you do not know whether the fake shuriken is heavier or lighter than the real ones.
Find the fake shuriken in 4 moves using the scales (meaning you're only allowed to place the shurikens on the balancing scale 4 times), and not hurting the shopkeeper with it.
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Post by Ark on Mar 7, 2006 15:46:47 GMT -5
COME ON, IT"S NOT THAT HARD THIS TIME
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me
Forum Newbie
Yeah Hikaru and Kaoru!
Posts: 48
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Post by me on Mar 8, 2006 12:53:22 GMT -5
... not hurt the shop keeper but he gave you a fake shuriken... i can't do it grrrr
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Post by Ark on Mar 8, 2006 21:32:25 GMT -5
ok, since nobody is trying, here's the answer:
Divide the 20 shurikens into 4 piles, 3 piles of 6 and 1 pile of 2. That means we have groups A, B and C with 6 shurikens and group D with 2 shurikens. This question can be solved in many ways, depends on how the weight balances out. I will go through all possibilities.
Solution 1. First weigh A with B. Say it balances out. Then weigh either A or B with C. Say it balances out too. Then you will be left with D, and you know the fake shuriken is in D. Take 2 shurikens out from either A, B or C, and weigh it with D. You will now determine whether the fake shuriken is lighter or heavier (Heavier if the D pile is heavier and vice versa). Weigh the last two shurikens in D and voila! Problem solved.
Solution 2. Weigh A and B. Say it balances out. Then weight either A or B with C. Doesnt balance out. If C was heavier we know that the fake shuriken inside C is heavier and vice versa. Break the C pile into groups E and F, E having 4 shurikens and F 2 shurikens. Weigh pile E with itself ( 2 - 2 ). If it balances out den the fakey is in pile F. If not its in pile E. Since we already know that whether the fake shuriken is heavier or lighter, we can easily determine where it is. Just say we found out the fakey is heavier. If the E pile was unbalanced we take the heavier pile, and do the last weigh! If it was pile F, well.. i guess everything reveals itself... =)
Solution 3. Weigh A and B. Doesnt balance out. Note which is heavier and which is lighter. Weight either one with C. Lets say its A with C. Balances out. So the fakey is in pile B. If B was the heavier pile earlier then the fakey is heavier and vice versa. If A and C doesnt balance out then the fakey is in pile A. Again, whether the fakey is heavier or lighter is determined as above. We have 2 more times to use the balancing scales. Like in Solution 2, break the fakey pile into 4's and 2's, and repeat the above! =)
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Post by Ark on Mar 8, 2006 21:33:57 GMT -5
Here's a riddle:
A voice said to you "Coconuts, $5 a dozen" With your lightning quick arithmatic you calculated that if you sold those same coconuts to the coconut air assault team for the going rate of $3 per dozen that in no time at all you would be a millionare. When I met you 15 seconds ago you told me the words you've just read. I ain't trying to be nosy but now that you've drug me this far, explain your math or quite lyin' and tell me your TRUE financial status!
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me
Forum Newbie
Yeah Hikaru and Kaoru!
Posts: 48
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Post by me on Mar 9, 2006 12:22:23 GMT -5
what kind of dollars? as if the person is selling them in candian dollars and you're going to sell them in american dollars you'd get a profit. also there are 2 definitions for a dozen, but i'm guessing that doesn't matter in this riddle...
btw i don't know the american to canadian dollar conversion so i could wrong about that.
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Post by Ark on Mar 9, 2006 15:07:25 GMT -5
they're almost equal now, so it is irrelivant, 12 to a dozen, and it has to do with your previous satus
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