Capt. Orygun
Win the Day
CAL wins
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Originally posted by SiR Kid+Jun 10 2004, 04:19 AM-->ndogg@Jun 10 2004, 01:05 AM
Here is a real brain teaser with a real solution. it is a little tricky but it CAN BE DONE without any bullshit tricks:
you have 8 identical coins. and a balance (where you can compare weights). you are allowed to use the balance 3 times only. one of the coins is a different weight than the other 7. wich one is it and is it heavier or lighter?
this question was asked to a friend of mine during a microsoft interview.
There is no way to tell from the information given.
BUT, the fastest way to find out which, and if heavier or lighter is listed here.
Weight 4 and 4. Which side is heavier?
Remove 1 of each side.
Weigh 3 and 3. Which side is heavier? If same, then the coins you removed from the previous step were different from each other. Weigh one against one of the remaining 6 to find the oddball.
If the 3 and 3 are still different, remove one from each side and weigh again.
Repeat til you find the oddball.
Originally posted by Silverchild79@Jun 10 2004, 05:46 AM
CAL wins
Originally posted by SiR Kid@Jun 10 2004, 06:24 AM
Done. You found the odd coin. BUT this is ONLY if you know wether the coin is ligher or heavier to begin with.
Originally posted by Silverchild79@Jun 10 2004, 12:24 PM
no you:
1. wieght the coins four a side, one side will be heavier, discard the light side (1 scale use)
2. Split the remianing four coins into stacks of two and weight them, discard the lighter stack. You should have two coins left (scale use two)
3. Of the remianing two coins determine which is heavier with your last use of the scale (3)
NEXT
nope. if you put 4 on each side, you don't know if the coin is lighter or heavier so how do you know what side to discard?
THERE IS AN ANSWER. i promise you.
Originally posted by ndogg@Jun 10 2004, 12:05 AM
just bring the line through the house not under it. then its 2-d. its a stupid trick question any way you look at it. if you look at it with graph theory (wich i have done) there is no solution. unless you use a special 2-d surface called a torus:
Originally posted by ndogg+Jun 10 2004, 12:45 PM-->Silverchild79@Jun 10 2004, 12:24 PM
no you:
1. wieght the coins four a side, one side will be heavier, discard the light side (1 scale use)
2. Split the remianing four coins into stacks of two and weight them, discard the lighter stack. You should have two coins left (scale use two)
3. Of the remianing two coins determine which is heavier with your last use of the scale (3)
NEXT
nope. if you put 4 on each side, you don't know if the coin is lighter or heavier so how do you know what side to discard?
THERE IS AN ANSWER. i promise you.
Originally posted by Silverchild79+Jun 10 2004, 03:52 PM-->Originally posted by ndogg@Jun 10 2004, 12:45 PM
Silverchild79@Jun 10 2004, 12:24 PM
no you:
1. wieght the coins four a side, one side will be heavier, discard the light side (1 scale use)
2. Split the remianing four coins into stacks of two and weight them, discard the lighter stack. You should have two coins left (scale use two)
3. Of the remianing two coins determine which is heavier with your last use of the scale (3)
NEXTÂ
nope. if you put 4 on each side, you don't know if the coin is lighter or heavier so how do you know what side to discard?
THERE IS AN ANSWER. i promise you.
it's impossible to do in 3 uses of the scale unless you get lucky or you can tell wich is diff with your hands
Originally posted by Silverchild79+Jun 10 2004, 03:52 PM-->Originally posted by ndogg@Jun 10 2004, 12:45 PM
Silverchild79@Jun 10 2004, 12:24 PM
no you:
1. wieght the coins four a side, one side will be heavier, discard the light side (1 scale use)
2. Split the remianing four coins into stacks of two and weight them, discard the lighter stack. You should have two coins left (scale use two)
3. Of the remianing two coins determine which is heavier with your last use of the scale (3)
NEXTÂ
nope. if you put 4 on each side, you don't know if the coin is lighter or heavier so how do you know what side to discard?
THERE IS AN ANSWER. i promise you.
it's impossible to do in 3 uses of the scale unless you get lucky or you can tell wich is diff with your hands
Originally posted by Airjockie@Jun 10 2004, 04:45 PM
OK.....
Now tell me how a bumble bee can fly....
It is litterally impossible...the wings are to small, and the body is too big and heavy...but yet it can fly....but how
now no googleing....