conster
Aug 1 2004, 01:31 AM
Part I - there are 12 balls same size same weight same color, everything the same except one all that is heavier than the others... u have a balance scale (the one for the libra sign) how do u tell which is the heavier ball? u can only weigh 3times.
Part II - Same scenario, except this time u dont knoe if the ball is heavier or not, u can weigh 3times. how u do it?
conster
Aug 1 2004, 01:43 AM
ok.. i figured out the first part...
first u put 6 and 6 on each scale, since the "odd" ball is heavier, that means its gonna be on the heavier side..
so u take the 6balls that are heavier and split into 3... and then take the heavier 3 and put one on each scale, if they're both equal then the one u didnt put is the "odd" one.. heh
i need help! on the second one
Levy2k6
Aug 1 2004, 01:18 PM
i don't understand the question..... grr.
x hYpErRoSeY x
Aug 1 2004, 02:25 PM
lol im totally confused sry
highly_evolved
Aug 2 2004, 05:21 AM
ya i got the first one. i heard this question before and remember how i did it hehe... i will b thinking about the asnwer to part 2...
ComradeRed
Aug 2 2004, 08:13 AM
The second scenario works exactly the same as the first one.
Stage one, you put 6 on each. If no ball is heavier, tyhey are equal. If one is heavier, than your solution stands.
sheepy
Aug 2 2004, 08:21 PM
UM. could u repeat dat in english plz
slurp
Aug 2 2004, 08:25 PM
uh lol, seems like youre better at this
mai_z
Aug 2 2004, 09:29 PM
ur problem confuzzling, but if I understand correctly, what ComradeRed said should be exactly right
AznKutie
Aug 2 2004, 09:30 PM
ackk...kunfused....very, very kunfused!
uLoVeMikeRoch
Aug 2 2004, 11:24 PM
Holy shit TRIPLE POSTING, thats just crazy
kyuubi319
Aug 3 2004, 11:19 AM
yerp, comradered is right, i think
co0nster421
Aug 3 2004, 12:58 PM
stage one : split the group in half. the heavier six has the heavier ball
stage two: split the heavier group into 3. heavier 3 has the heavier ball
stage three: this has two senarios:
you weigh only two of the balls
-if one ball is heavier, than you got the heaviest ball
-if both balls balance, than the extra ball is the heaviest
x AZN D0RKii x
Aug 3 2004, 01:19 PM
whoa S0 *confuseing ..

heh or maybe i`m just not smart
conster
Aug 3 2004, 01:33 PM
yea co0nster421 got part 1
part2 cant be done like part 1 cuz u dont knoe if the "odd ball" is heavier or not.. in part 1 i told u its gonna be heavier thats why when u weigh 6 and 6, u take the 6 that are heavier..
in part 2, u dont knoe if the odd ball is heavier or lighter tho lol lets say the odd one is lighter, then u choose the lighter side of course but u dont knoe it, thats thing ... basically part2 asks how do u find the "odd" ball by only weighing the 12balls 3times
F1R3B4T
Aug 5 2004, 08:43 PM
alright alright thsi is how u do it:
Number the balls 1 to 12. Weigh 1, 2, 3, and 4 against 5, 6, 7, and 8.
If (1, 2, 3, 4) and (5, 6, 7, 8) balance:
Weigh 9 and 10 against 11 and 8 (we know 8 is not the odd ball).
If (9, 10) and (11, 8) balance: then 12 is the odd one.
Weigh 12 against any other to find out if it is heavy or light.
If (9, 10) and (11, 8) do not balance: suppose 11 and 8 are heavier,
than 9 and 10; then either 11 is heavy, or 9 is light, or 10 is light.
Weigh 9 against 10; if they balance, 11 is heavy; if they do not,
the lighter of 9 and 10 is the odd ball.
(Similar argument if 11 and 8 are lighter than 9 and 10).
If (1, 2, 3, 4) and (5, 6, 7, 8) do not balance:
Suppose 5, 6, 7, and 8 are heavier than 1, 2, 3, & 4. Then: one of
(1, 2, 3, or 4) is light, or else one of (5, 6, 7, or 8) is heavy.
Weigh 1, 2, and 5 against 3, 6, and 9.
If they balance: then either 7 is heavy, or 8 is heavy, or 4 is light.
Weigh 7 against 8; if they balance, 4 is the odd ball, otherwise the
heavier of 7 and 8 is the odd ball.
If (1, 2, 5) and (3, 6, 9) do not balance: suppose 1, 2, and 5 are lighter
than 3, 6, and 9; then either 6 is heavy, or 1 is light, or 2 is light.
Weigh 1 against 2 to find out which one of the three choices is true.
Otherwise, suppose 1, 2, and 5 are heavier than 3, 6, and 9; then either 3
is light, or 5 is heavy.
Weigh 3 against (say) 2 to find out which of the two choices is true.
(Similar argument if 1, 2, and 5 are lighter than 3, 6, and 9).
rAnd0m_strang3r
Aug 6 2004, 12:01 AM
oh wow.. i am so bad a logic problems, i would never have thought of the solution.. hmm i will ask some of my friends i they can solve it ^-^