2: 28; 3: 256

2) 2, 4, 6, 9, 13, 19, ？
A.28　B.29　C.30　D.31
2 + 4 = 6 ---> 6 - 6 = 0
4 + 6 = 10 ---> 10 - 9 = 1
6 + 9 = 15 ---> 15 - 13 = 2
9 + 13 = 22 ---> 22 - 19 = 3
13 + 19 = 32 ---> 32 - 4 = 28
------------------------------------------
3) -2, 1/2, 4, 2, 16, ？
A. 32　B. 64　C. 128　D.256

1/2 ^ (-2) = 4
4 ^ (1/2) = 2
2 ^ 4 = 16
16 ^ 2 = 256

所有跟帖： 

• 玩一把。：-） -^V^- ♂ (425 bytes) () 09/19/2009 postreply 11:22:01

• Would you please show your reasoning for 4 and 5? Thanks! -innercool- ♀ (0 bytes) () 09/19/2009 postreply 14:00:54

• 回复：Would you please show your reasoning for 4 and 5? Thanks! -^V^- ♂ (513 bytes) () 09/19/2009 postreply 14:50:52

• 回复：回复：Would you please show your reasoning for 4 and 5? Thanks! -jinhr- ♂ (276 bytes) () 10/04/2009 postreply 20:29:59