that's easy, i only took 30secs of it!
& k+ s" O/ h" ?0 C6 U. k* V公仔箱論壇1st: seperate 2 groups of the ball, which are 6 each of the group, scal them up and must be one of them are heavier than the another, and then. J) o/ ^& d1 E* f" B0 ~) ?
2nd: seperate the heavier group's ball into 3 balls each and scale again, then we can tell one of these will heavier than the another and took the heavier group's ball into three group of one of each in the group, and scal the 3rd time, if the result of 3rd scal come with eaven that meants the 3rd ball is the heavy one out of the 12 balls, or if the result come of one of them is heavy then the one on the scal is heaier than the 11balls! Q.E.D. |
發表於 2009-4-13 05:53 PM
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