n次可稱（3^n-3）/2個，並指出它是過輕或過重。

如果另外有一個好球，或者不需要知道過輕或過重，n次可稱（3^n-1）/2個。

所有跟帖： 

• 康MM的公式正確, 3次隻能稱12個球,而4次能稱39個球. -Blue_Diamond- ♂ (21 bytes) () 05/02/2010 postreply 09:49:20

• 3 times are enough for 13 balls -jinjing- ♀ (263 bytes) () 05/02/2010 postreply 12:30:37

• 回複：3 times are enough for 13 balls -wushuihe- ♂ (93 bytes) () 05/02/2010 postreply 15:39:14

• not big deal,careless,3 times are enough for 13 balls -jinjing- ♀ (273 bytes) () 05/02/2010 postreply 18:03:21

• 回複：not big deal,careless,3 times are enough for 13 balls -wushuihe- ♂ (25 bytes) () 05/03/2010 postreply 01:52:46

• 4 times are enough for4 2 ,but you need 5 times. -Jinjing- ♀ (109 bytes) () 05/02/2010 postreply 14:03:37

• 4 times are enough for 42 balls, you need 5 times. -jinjing- ♀ (168 bytes) () 05/02/2010 postreply 14:12:59

• 回複：4 times are enough for 42 balls, you need 5 times. -康MM- ♀ (123 bytes) () 05/03/2010 postreply 03:59:22